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Abstract:

According to the first invention group there are provided conjugated
compounds having two or more groups represented by the following formula
(I) or the following formula (II):
##STR00001##
wherein one of Ar and Ar' represents a C6 or greater divalent aromatic
hydrocarbon group and the other represents a C4 or greater divalent
heterocyclic group, wherein the groups each may have a substituent, with
the proviso that the groups as a whole contain no fluorine atoms, R1
and R2 each independently represent a hydrogen atom, a halogen atom
or a monovalent group, and Ar'' represents a trivalent aromatic
hydrocarbon or trivalent heterocyclic group; when the conjugated compound
has two or more groups represented by formula (I), the portion excluding
these groups contain no fluorine atoms.
According to the second group of the present invention there are provided
nitrogen-containing fused-ring compounds represented by the following
formula (α-I):
##STR00002##
in formula (α-I), R21 and R22 each independently represent
a hydrogen atom, a halogen atom or an optionally substituted monovalent
group, and Z21 and Z22 each independently represent any one of
the groups represented by the following formulas
(α-i)-(α-ix);
##STR00003##
wherein R23, R24, R25 and R26 each independently
represent a hydrogen atom, a halogen atom or a monovalent group, and
R23 and R24 may bond together to form a ring, the left side and
the right side of the group represented by formula (α-viii) may be
interchanged.

Claims:

1. A conjugated compound having two or more groups represented by the
following formula (I) or formula (II): ##STR00068## wherein one of Ar and
Ar' represents a C6 or greater divalent aromatic hydrocarbon group and
the other represents a C4 or greater divalent heterocyclic group, wherein
the groups each may have a substituent, with the proviso that the groups
as a whole contain no fluorine atoms, R1 and R2 each
independently represent a hydrogen atom, a halogen atom or a monovalent
group, and Ar'' represents a trivalent aromatic hydrocarbon or trivalent
heterocyclic group, which may have a substituent; when the conjugated
compound has two or more groups represented by formula (I), the portion
excluding these groups contain no fluorine atoms.

2. The conjugated compound according to claim 2, wherein the group
represented by formula (I) is a group represented by the following
formula (III): ##STR00069## wherein R1 and R2 have the same
definitions as above, each R0 represents a hydrogen atom, a C1 to
C20 alkyl group or a C1 to C20 alkoxy group, one of Z1 and Z1'
represents a group represented by the following formula (i) and the other
represents any one of the groups represented by the following formulas
(ii)-(ix), R3, R4, R5 and R6 each independently
represent a hydrogen atom or a monovalent group, and R3 and R4
may bond together to form a ring; a plurality of the groups in R0
may be the same or different. ##STR00070##

3. The conjugated compound according to claim 2 having two or more groups
represented by formula (III).

4. The conjugated compound according to claim 4, wherein the conjugated
compound having two or more groups represented by formula (III) is a
conjugated compound represented by the following formula (V):
##STR00071## wherein R0, R1, R2, Z1 and Z1' have
the same definitions as above, Ar1, Ar2 and Ar3 each
independently represent a C6 or greater divalent aromatic hydrocarbon or
C4 or greater divalent heterocyclic group, which may have a substituent,
with the proviso that the groups as a whole contain no fluorine atoms,
and m, n and p each independently represent an integer of 0-6; a
plurality of the groups in R0, R1, R2, Z1 and
Z1' may be the same or different.

5. The conjugated compound according to claim 4, wherein at least one
group of Ar1, Ar2 and Ar3 is an optionally substituted
thienylene group, with the proviso that the group as a whole contains no
fluorine atoms.

6. The conjugated compound according to claim 1, wherein the group
represented by formula (II) is a group represented by the following
formula (IV): ##STR00072## wherein R10 represents a hydrogen atom, a
fluorine atom, a C1 to C20 alkyl group, a C1 to C20 fluoroalkyl group, a
C1 to C20 alkoxy group or a C1 to C20 fluoroalkoxy group, Z2
represents any one of the groups represented by the following formulas
(xi)-(xix), R13, R14, R15 and R16 each independently
represent a hydrogen atom, a halogen atom or a monovalent group, and
R13 and R14 may bond together to form a ring. ##STR00073##

7. The conjugated compound according to claim 6 having two or more groups
represented by formula (IV).

8. The conjugated compound according to claim 7, wherein the conjugated
compound having two or more groups represented by formula (IV) is a
conjugated compound represented by the following formula (VI):
##STR00074## wherein each R10 and each Z2 have the same
definitions as above, Ar4, Ar5 and Ar6 each independently
represent a C6 or greater divalent aromatic hydrocarbon or C4 or greater
divalent heterocyclic group, which may have a substituent), and q, r and
s each independently represent an integer of 0-6; a plurality of the
groups in R10 and Z2 may be the same or different.

9. The conjugated compound according to, claim 6, wherein each Z2 is
a group represented by formula (xii).

10. An organic thin film comprising the conjugated compound according to
claim 1.

11. An organic thin-film device comprising the organic thin film according
to claim 10.

12. An organic thin-film transistor comprising:a source electrode and
drain electrode;an organic semiconductor layer that is to serve as a
current channel between the electrodes; anda gate electrode that is to
control the level of current flowing through the current channel;wherein
the organic semiconductor layer comprises the organic thin film according
to claim 10.

13. An organic solar cell comprising the organic thin film according to
claim 10.

14. An optical sensor comprising the organic thin film according to claim
10.

15. A nitrogen-containing fused-ring compound represented by the following
formula (α-I): ##STR00075## in formula (α-I), R21 and
R22 each independently represent a hydrogen atom, a halogen atom or
an optionally substituted monovalent group, and Z21 and Z22
each independently represent any one of the groups represented by the
following formulas (α-i)-(α-ix); ##STR00076## wherein
R23, R24, R25 and R26 each independently represent a
hydrogen atom, a halogen atom or a monovalent group, and R23 and
R24 may bond together to form a ring, the left side and the right
side of the group represented by formula (α-viii) may be
interchanged.

16. The nitrogen-containing fused-ring compound according to claim 15,
wherein Z21 and Z22 are groups represented by formula
(α-ii).

17. The nitrogen-containing fused-ring compound according to claim 15
represented by the following formula (α-I-I): ##STR00077## in
formula(α-I-I), Z21, Z22 and Z1' each independently
represent any one of the groups represented by formulas
(α-i)-(α-ix), R1 and R2 each independently
represent a hydrogen atom, a halogen atom or a monovalent group, and each
R0 represents a hydrogen atom, a C1 to 20 alkyl group or a C1 to 20
alkoxy group; a plurality of the groups in R0 may be the same or
different.

18. The nitrogen-containing fused-ring compound according to claim 15,
wherein at least one of R21 and R22 is a group represented by
the following formula (IV): ##STR00078## wherein R10 represents a
hydrogen atom, a fluorine atom, a C1 to-C20 alkyl group, a C1 to C20
fluoroalkyl group, a C1 to C20 alkoxy group or a C1 to C20 fluoroalkoxy
group, Z2 represents any one of the groups represented by the
following formulas (xi)-(xix), R13, R14, R15 and R16
each independently represent a hydrogen atom, a halogen atom or a
monovalent group, and R13 and R14 may bond together to form a
ring. ##STR00079##

19. A nitrogen-containing fused-ring polymer having a repeating unit
represented by the following formula (α-II): ##STR00080## in
formula (α-II), Z21 and Z22 each independently represent
any one of the groups represented by the following formulas
(α-i)-(α-ix); ##STR00081## wherein R23, R24,
R25 and R26 each independently represents a hydrogen atom, a
halogen atom or a monovalent group, and R23 and R24 may bond
together to form a ring; the left side and the right side of the group
represented by formula (α-viii) may be interchanged.

20. The nitrogen-containing fused-ring polymer according to claim 19,
wherein Z21 and Z22 are groups represented by formula
(α-ii).

21. The nitrogen-containing fused-ring polymer according to, claim 19
having at least one repeating unit represented by the formula
(α-II) and at least one repeating unit represented by the following
formula (α-III):[Chemical Formula 15] Ar21 (α-III)in
formula (α-III), Ar21 represents a divalent aromatic
hydrocarbon or divalent heterocyclic group, which may have a substituent.

22. The nitrogen-containing fused-ring polymer according to claim 21,
wherein Ar21 is a group represented by the following formula
(α-IV): ##STR00082## in formula (α-IV), R27 and R28
each independently represent a hydrogen atom, a halogen atom or a
monovalent group, and Z23 represents any one of the groups
represented by the following formulas (α-i)-(α-ix); R27
and R28 may bond together to form a ring; ##STR00083## wherein
R23, R24, R25 and R26 each independently represent a
hydrogen atom, a halogen atom or a monovalent group, and R23 and
R24 may bond together to form a ring; the left side and the right
side of the group represented by formula (α-viii) may be
interchanged.

23. The nitrogen-containing fused-ring polymer according to claim 22,
wherein Z23 is a group represented by formula (α-ii).

24. An organic thin film comprising the nitrogen-containing fused-ring
compound according to claim 15.

25. An organic thin-film device comprising the organic thin film according
to claim 24.

26. An organic thin-film transistor comprising the organic thin film
according to claim 24.

27. An organic solar cell comprising the organic thin film according to
claim 24.

28. An optical sensor comprising the organic thin film according to claim
24.

29. An organic thin film comprising the nitrogen-containing fused-ring
polymer according to claim 19.

30. An organic thin-film device comprising the organic thin film according
to claim 29.

31. An organic thin-film transistor comprising the organic thin film
according to claim 29.

32. An organic solar cell comprising the organic thin film according to
claim 29.

33. An optical sensor comprising the organic thin film according to claim
29.

Description:

TECHNICAL FIELD

[0001]The present invention relates to a conjugated compound, a
nitrogen-containing fused-ring compound, a nitrogen-containing fused-ring
polymer, an organic thin film, and an organic thin film device.

BACKGROUND ART

[0002]A variety of conjugated compounds have been developed as organic
n-type semiconductors, for use as materials in organic thin film devices
such as organic transistors, organic solar cells and optical sensors.
Specific examples include compounds with fluoroalkyl groups introduced
into oligothiophenes (Patent documents 1-4).

[0004]In recent years, much research has been conducted on compounds
having thiophene rings, fluoroalkyl groups introduced into which, with
increased electron acceptability of π-conjugated compounds, as
electron transport materials for organic n-type semiconductors and the
like (Patent document 1).

[0005]On the other hand, several polythiophenes having crosslinked
structures are also being studied in order to improve planarity in the
molecular structure (Patent document 5).

[0006]The compounds described in Patent documents 1-4, however, cannot be
utilized as organic n-type semiconductors with satisfactory electron
transport properties.

[0007]The performance of even the known materials described in Patent
documents 1 and 5, as organic n-type semiconductors, is not sufficient,
and organic n-type semiconductors with further improved electron
transport properties are desired.

[0008]It is therefore an object of the present invention to provide novel
compounds and novel polymers that can be used as organic n-type
semiconductors with excellent electron transport properties. It is
another object of the present invention to provide organic thin films
containing the novel compounds and/or novel polymers and organic
thin-film devices comprising the organic thin films.

Means for Solving the Problems

[0009]The first invention group will be explained first.

[0010]In order to achieve the object stated above, the present invention
provides a conjugated compound having two or more groups represented by
the following formula (I) or the following formula (II).

##STR00004##

[0011]One of Ar and Ar' represents a C6 or greater divalent aromatic
hydrocarbon group and the other represents a C4 or greater divalent
heterocyclic group, wherein the groups each may have a substituent, with
the proviso that the groups as a whole contain no fluorine atoms, R1
and R2 each independently represent a hydrogen atom, a halogen atom
or a monovalent group, and Ar'' represents a trivalent aromatic
hydrocarbon or trivalent heterocyclic group, which may have a
substituent. However, when the conjugated compound has two or more groups
represented by formula (I), the portion excluding these groups contain no
fluorine atoms.

[0012]A conjugated compound with such a backbone has an excellent packing
property between molecules, and can exhibit a sufficiently low LUMO due
to introduction of the α-fluoroketone structure
(--C(═O)--C(F)<). The conjugated compound is therefore
sufficiently suitable as an n-type semiconductor with excellent electron
injection and electron transport properties. Such compounds are also
chemically stable and have excellent solubility in solvents, and
therefore by allowing thin films to form using the conjugated compounds,
the organic thin-film devices with excellent performance can be produced.

[0016]In order to achieve the object stated above, the present invention
further provides nitrogen-containing fused-ring compounds represented by
the following formula (α-I).

##STR00005##

In formula (α-I), R21 and R22 each independently represent
a hydrogen atom, a halogen atom or an optionally substituted monovalent
group, and Z21 and Z22 each independently represent any one of
the groups represented by the following formulas
(α-i)-(α-ix).

##STR00006##

In the formulas, R23, R23, R25 and R26 each
independently represents a hydrogen atom, a halogen atom or a monovalent
group, and R23 and R24 may bond together to form a ring. The
left side and the right side of the group represented by formula
(α-viii) may be interchanged.

[0017]The present invention still further provides a nitrogen-containing
fused-ring polymer having a repeating unit represented by the following
formula (α-II).

##STR00007##

[0018]In formula (α-II), Z21 and Z22 each independently
represent any one of the groups represented by the following formulas
(α-i)-(α-ix).

##STR00008##

[0019]In the formulas, R23, R24, R25 and R26 each
independently represents a hydrogen atom, a halogen atom or a monovalent
group, and R23 and R24 may bond together to form a ring. The
left side and the right side of the group represented by formula
(α-viii) may be interchanged.

[0020]Nitrogen-containing fused-ring compounds and nitrogen-containing
fused-ring polymers comprising such a backbone have satisfactory
π-conjugated planarity between the rings and can exhibit a
sufficiently low LUMO due to introduction of the nitrogen-containing
fused rings, and can therefore be used as organic n-type semiconductors
with excellent electron transport properties. Such nitrogen-containing
fused-ring compounds and nitrogen-containing fused-ring polymers are also
chemically stable and have excellent solubility in organic solvents, and
therefore by allowing thin films to form using them, the organic
thin-film devices with excellent performance can be produced.

[0021]The nitrogen-containing fused-ring compounds and nitrogen-containing
fused-ring polymers of the present invention are also environmentally
stable and have excellent solubility in organic solvents, and can
therefore be used to form thin films to allow production of organic
thin-film devices with stable performance even in ordinary air.

[0024]According to the first invention group it is possible to provide
novel conjugated compounds that can be used as organic n-type
semiconductors with excellent electron transport properties. It is also
possible to provide organic thin films containing the novel conjugated
compounds, and organic thin-film devices comprising the organic thin
films.

[0025]According to the second invention group, it is possible to provide
novel nitrogen-containing fused-ring compounds and novel
nitrogen-containing fused-ring polymers that can be used as organic
n-type semiconductors with excellent electron transport properties. It is
also possible to provide organic thin films containing the
nitrogen-containing fused-ring compounds or nitrogen-containing
fused-ring polymers, and organic thin-film devices comprising the organic
thin films.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is a schematic cross-sectional view of an organic thin-film
transistor according to a first embodiment.

[0027]FIG. 2 is a schematic cross-sectional view of an organic thin-film
transistor according to a second embodiment.

[0028]FIG. 3 is a schematic cross-sectional view of an organic thin-film
transistor according to a third embodiment.

[0029]FIG. 4 is a schematic cross-sectional view of an organic thin-film
transistor according to a fourth embodiment.

[0030]FIG. 5 is a schematic cross-sectional view of an organic thin-film
transistor according to a fifth embodiment.

[0031]FIG. 6 is a schematic cross-sectional view of an organic thin-film
transistor according to a sixth embodiment.

[0032]FIG. 7 is a schematic cross-sectional view of an organic thin-film
transistor according to a seventh embodiment.

[0033]FIG. 8 is a schematic cross-sectional view of a solar cell according
to an embodiment.

[0034]FIG. 9 is a schematic cross-sectional view of an optical sensor
according to a first embodiment.

[0035]FIG. 10 is a schematic cross-sectional view of an optical sensor
according to a second embodiment.

[0036]FIG. 11 is a schematic cross-sectional view of an optical sensor
according to a third embodiment.

[0037]FIG. 12 is a drawing showing the torsional angle formed between the
ring of the repeating unit represented by formula (α-II) and the
ring of the repeating unit represented by formula (α-IV).

[0038]FIG. 13 is a drawing showing the torsional angles formed between
adjacent bonded molecular rings in compound α-I.

[0039]FIG. 14 is a drawing showing the crystal structure of compound
α-I.

[0041]Preferred embodiments of the present invention will now be explained
in detail, with reference to the accompanying drawings as necessary.
Throughout the drawings, corresponding elements will be referred to by
like reference numerals and will be explained only once. Unless otherwise
specified, the vertical and horizontal positional relationships are based
on the positional relationships in the drawings. Also, the dimensional
proportions depicted in the drawings are not necessarily limitative.

[0042]The first invention group will be explained in detail first.

[0043]A conjugated compound of the present invention has two or more
groups represented by the above formula (I) or (II). A conjugated
compound, according to the present invention, is a compound comprising a
structure with a single bond and an unsaturated bond, lone electron pair,
radical or nonbonded orbital, alternately linked, in the main backbone,
with delocalization of electrons due to interaction between n-orbitals or
nonbonded orbitals, in part or across the entire main backbone. It is
preferable that the conjugated compounds are π-conjugated compounds
due to interaction between n-orbitals.

[0044]When the conjugated compound has two or more groups represented by
formula (I), the portion excluding the groups contain no fluorine atoms.
Such conjugated compounds have sufficiently high packing property between
molecules and are sufficiently suitable as re-type semiconductors with
excellent electron injection and electron transport properties.

[0045]A plurality of groups represented by formula (I) or (II) in the
conjugated compound may be the same or different, but it is preferable
that they are the same.

[0046]In formula (I), one of Ar and Ar' is a C6 or greater divalent
aromatic hydrocarbon group and the other is a C4 or greater divalent
heterocyclic group. These groups may have substituents, but contain no
fluorine atoms as a whole. It is preferable that Ar is a C4 or greater
divalent heterocyclic group and Ar' is a C6 or greater divalent aromatic
hydrocarbon group. R1 and R2 each independently represent a
hydrogen atom, a halogen atom or a monovalent group.

[0047]A divalent aromatic hydrocarbon group is an atomic group remaining
after removing two hydrogen atoms from a benzene ring or fused ring. The
number of carbon atoms in the divalent aromatic hydrocarbon group is
preferably 6 to 60 and more preferably 6 to 20. Examples of fused rings
include naphthalene, anthracene, tetracene, pentacene, pyrene, perylene
and fluorene. Preferred among these are atomic groups remaining after
removing two hydrogen atoms from a benzene, pentacene or pyrene ring. The
aromatic hydrocarbon groups may be optionally substituted. The numbers of
carbon atoms of the substituents are not included in the number of carbon
atoms in the divalent aromatic hydrocarbon groups. As substituents there
may be mentioned halogen atoms, saturated or unsaturated hydrocarbon
groups, aryl groups, alkoxy groups, arylalkyl groups, aryloxy groups,
monovalent heterocyclic groups, amino groups, nitro groups and cyano
groups.

[0048]A divalent heterocyclic group is an atomic group remaining after
removing two hydrogens from a heterocyclic compound. The number of carbon
atoms in the divalent heterocyclic group is preferably 4 to 60 and more
preferably 4 to 20. The divalent heterocyclic group may have
substituents, and the numbers of carbons of the substituents are not
included in the number of carbons in the divalent heterocyclic group. As
substituents there may be mentioned halogen atoms, saturated or
unsaturated hydrocarbon groups, aryl groups, alkoxy groups, arylalkyl
groups, aryloxy groups, monovalent heterocyclic groups, amino groups,
nitro groups and cyano groups. Examples of divalent heterocyclic groups
include atomic groups remaining after removing two hydrogen atoms from a
thiophene ring, thienothiophene ring, furan ring, pyrrole ring or
pyridine ring, and particularly atomic groups remaining after removing
two hydrogen atoms from a thiophene ring or thienothiophene ring can be
expected to exhibit characteristic electrical properties and novel
electrical properties not found in the prior art. It is preferable that
the divalent heterocyclic groups are divalent aromatic heterocyclic
groups.

[0049]A heterocyclic compound is an organic compound with a ring
structure, the elements composing the ring of which include not only
carbon but also heteroatoms such as oxygen, sulfur, nitrogen, phosphorus,
boron and silicon.

[0050]Examples of halogen atoms include fluorine atoms, chlorine atoms,
bromine atoms and iodine atoms. R1 and R2 are preferably
fluorine atoms, from the viewpoint of obtaining even lower LUMO.

[0051]The groups represented by the above formula (I) are preferably
groups represented by the following formula (III).

##STR00009##

[0052]In formula (III), R1 and R2 each independently represents
a hydrogen atom, a halogen atom or a monovalent group, and R0
represents hydrogen, a C1 to C20 alkyl group or a C1 to C20 alkoxy group,
wherein a plurality of the groups in R0 may be the same or
different. One of Z1 and Z1' is a group represented by the
following formula (i), and the other is a group represented by any one of
the following formulas (ii)-(ix). It is preferable that Z1' is a
group represented by the following formula (i), and Z1 is any one of
the groups represented by the following formulas (ii)-(ix). Also,
R3, R4, R5 and R6 each independently represent a
hydrogen atom or a monovalent group, and R3 and R4 may bond
together to form a ring.

##STR00010##

[0053]When the conjugated compound has two or more groups represented by
formula the (I) or (III), it is preferable that the compound is
represented by the following formula (V).

##STR00011##

[0054]In formula (V), R0, R1, R2, Z1 and Z1' have
the same definitions as above. Ar1, Ar2 and Ar3 each
independently represent a C6 or greater divalent aromatic hydrocarbon or
C4 or greater divalent heterocyclic group. These groups may have
substituents, but contain no fluorine atoms as a whole. As divalent
aromatic hydrocarbons and C4 or greater divalent heterocyclic groups
there may be mentioned the same groups as those mentioned for Ar and Ar'.
It is preferable that at least one of Ar1, Ar2 and Ar3 is
an optionally substituted thienylene group but it as a whole contains no
fluorine atoms. The letters m, n and p each independently represent an
integer of 0 to 6. When a plurality of the groups in R0, R1,
R2, Z1 and Z1' are present they may be the same or
different. From the viewpoint of more effectively exhibiting the effect
of the present invention, it is more preferable that R1 and R2
are fluorine atoms, Z1' is a group represented by formula (i) and
Z1 is a group represented by formula (ii). It is most preferable
that at least one of Ar1, Ar2 and Ar3 is a thienylene
group.

[0056]A trivalent aromatic hydrocarbon group is an atomic group remaining
after removing three hydrogen atoms from a benzene ring or fused ring.
The number of carbon atoms in the trivalent aromatic hydrocarbon group is
preferably 6 to 60 and more preferably 6 to 20. Examples of fused rings
include naphthalene, anthracene, tetracene, pentacene, pyrene, perylene
and fluorene. Particularly preferred among these are atomic groups
remaining after removing three hydrogen atoms from a benzene ring. The
aromatic hydrocarbon groups may be optionally substituted. The numbers of
carbon atoms of the substituents are not included in the number of carbon
atoms in the trivalent aromatic hydrocarbon groups.

[0057]A trivalent heterocyclic group is an atomic group remaining after
removing two hydrogen atoms from a heterocyclic compound. The number of
carbon atoms in the trivalent heterocyclic group is preferably 4 to 60
and more preferably 4 to 20. The trivalent heterocyclic group may have
substituents, and the numbers of carbons of the substituents are not
included in the number of carbons in the trivalent heterocyclic group.
Examples of trivalent heterocyclic groups include atomic groups remaining
after removing three hydrogens from a thiophene ring, thienothiophene
ring, furan ring, pyrrole ring or pyridine ring, and particularly atomic
groups remaining after removing three hydrogens from a thiophene ring or
thienothiophene ring can be expected to exhibit characteristic electrical
properties and novel electrical properties not found in the prior art. It
is preferable that the trivalent heterocyclic groups are trivalent
aromatic heterocyclic groups.

[0058]It is preferable that the groups represented by the above formula
(II) are groups represented by the following formula (IV).

##STR00012##

[0059]In formula (IV), R10 represents a hydrogen atom, a fluorine
atom, a C1 to C20 alkyl group, a C1 to C20 fluoroalkyl group, a C1 to C20
alkoxy group or a C1 to C20 fluoroalkoxy group, and Z2 represents
any one of the groups represented by the following formulas (xi)-(xix).
It is preferable that Z2 is a group represented by the following
formula (xii). Also, R13, R14, R15 and R16 each
independently represent a hydrogen atom, a halogen atom or a monovalent
group, and R13 and R14 may bond together to form a ring.

##STR00013##

[0060]When the conjugated compound has two or more groups represented by
formula (II) or (IV), it is preferably a compound represented by the
following formula (VI).

##STR00014##

[0061]In formula (VI), each R10 and each Z2 have the same
definitions as above, and a plurality of the groups in R10 and
Z2 may be the same or different. Ar4, Ar5 and Ar6
each independently represent a C6 or greater divalent aromatic
hydrocarbon or C4 or greater divalent heterocyclic group, wherein the
groups may be optionally substituted. As divalent aromatic hydrocarbons
and C4 or greater divalent heterocyclic groups there may be mentioned the
same groups as those mentioned for Ar and Ar'. It is more preferable that
at least one of Ar4, Ar5 and Ar6 is an optionally
substituted thienylene group. The letters q, r and s each independently
represent an integer of 0 to 6. From the viewpoint of more effectively
exhibiting the effect of the present invention, it is preferable that
Z2 is a group represented by formula (xii).

[0062]As alkyl groups for R0 and R10 there may be mentioned C1
to C20 straight-chain, branched or cyclic alkyl groups, with C1 to C12
straight-chain, branched and cyclic alkyl groups being preferred.
Examples of such alkyl groups include methyl groups, ethyl groups,
n-propyl groups, iso-propyl groups, n-butyl groups, iso-butyl groups,
tert-butyl groups, 3-methylbutyl groups, pentyl groups, hexyl groups,
2-ethylhexyl groups, heptyl groups, octyl groups, nonyl groups, decyl
groups, lauryl groups, cyclopropyl groups, cyclobutyl groups, cyclopentyl
groups, cyclohexyl groups, cycloheptyl groups, cyclooctyl groups,
cyclononyl groups and cyclododecyl groups. As alkoxy groups there may be
mentioned C1 to C20 alkoxy groups comprising the above alkyl groups in
their structures. As alkoxy groups there may be mentioned C1 to C20
straight-chain, branched or cyclic alkoxy groups comprising the above
alkyl groups in their structures, and it is preferable that the alkoxy
groups comprise C1 to C12 straight-chain, branched and cyclic alkyl
groups. As fluoroalkyl groups for R10 there may be mentioned the
aforementioned alkyl groups having some or all of their hydrogen atoms
replaced with fluorine atoms, and it is preferable that the fluoroalkyl
groups comprise C1 to C12 straight-chain, branched and cyclic fluoroalkyl
groups. As fluoroalkoxy groups there may be mentioned C1 to C20
fluoroalkoxy groups comprising the above fluoroalkyl groups in their
structures, and it is preferable that the fluoroalkoxy groups comprise C1
to C12 straight-chain, branched and cyclic fluoroalkyl groups.

[0066]There are no particular restrictions on alkanoyl groups, and
examples include formyl groups, acetyl groups, propionyl groups,
isobutyryl groups, valeryl groups and isovaleryl groups. The same is
applied for groups comprising alkanoyl groups in their structures (for
example, alkanoyloxy groups and alkanoylamino groups). A "C1 alkanoyl
group" is formyl groups, which also is applied for groups containing
alkanoyl groups in their structures.

[0067]The conjugated compounds of the present invention are expected to
have high electron transport properties as organic n-type semiconductors.
In order to make the effect increase, it is preferable to make the
compounds readily adopt a π-π stack structure by increasing the
planarity of the π-conjugated structure other than the groups
represented by formula (I) or (II). From this viewpoint, Ar1,
Ar2 and Ar3 in formula (V) and Ar4, Ar5 and Ar6
in formula (VI) preferably have structures comprising fused rings or
thiophene rings. It is especially preferable that the structure comprises
the thiophene backbone since the plane spacing in the π-π stack
structure can be reduced. From the viewpoint of improving solubility in
organic solvents and retaining π-conjugated planarity, it is
preferable that Ar1, Ar2, Ar3, Ar4, Ar5 and
Ar6 have substituents. However, the compound as a whole preferably
contains no fluorine atoms.

[0068]A conjugated compound of the present invention has two or more
groups represented by formula (I), (II), (III) or (IV). From the
viewpoint of increasing the electron transport property, it is preferable
that the conjugated compound is a compound represented by the above
formula (V) or (VI). As specific compounds represented by the above
formula (V) or (VI) there may be mentioned compounds represented by the
following formulas (1)-(20).

##STR00015## ##STR00016## ##STR00017##

[0069]In these formulas, R represents a hydrogen atom, a C1 to C20 alkyl
group or a C1 to C20 alkoxy group. R*, R' and R'' represent hydrogen
atoms, fluorine atoms, or C1 to C20 alkyl groups, C1 to C20 fluoroalkyl
groups, C1 to C20 alkoxy group or C1 to C20 fluoroalkoxy groups. A
plurality of the groups in R, R*, R' and R'' may be the same or
different. Of these, it is preferable that R, R* and R' are preferably
hydrogen atoms or C1 to C20 alkyl groups, and R'' is a fluorine atom or
C1 to C20 fluoroalkyl group.

[0070]The conjugated compounds of the present invention have a reduction
potential based on ferrocene, as determined by electrochemical
measurement (cyclic voltammetry), of preferably -2.0 V to +0.5 V and more
preferably -1.8 V to +0.2 V. If the reduction potential is within this
numerical range, the conjugated compound will be sufficiently suitable as
an n-type semiconductor with excellent electron injection and excellent
electron transport properties. The reduction potential can be measured by
the following method. The supporting electrolyte, solvent and electrodes
used for the measurement are not limited to the examples mentioned below,
and may be as desired so long as they permit similar measurement.

[0071]The material to be measured is dissolved to about 0.1-2 mM in an
organic solvent containing about 0.1 mol/L tetrabutylammonium perchlorate
and tetrabutylammonium hexafluorophosphate, as examples of supporting
electrolytes. The obtained solution is subjected to dry nitrogen
bubbling, reduced pressure deaeration, ultrasonic irradiation or the like
to remove the oxygen, and then a platinum electrode or glassy carbon
electrode, for example, is used as the work electrode with a platinum
electrode, for example, as the counter electrode, for electrolytic
reduction from an electrically neutral state at a sweep rate of 100
mV/sec. The potential of the first peak value detected during
electrolytic reduction is compared with the oxidation-reduction potential
of a reference material such as ferrocene, to obtain the oxidation (or
reduction) potential for the material being measured. The value of the
oxidation (or reduction) potential obtained in this manner converted
based on ferrocene is the reduction potential according to the present
invention.

[0072]A method for producing a conjugated compound of the present
invention will now be explained. The conjugated compound can be produced
by reacting compounds represented by the following formulas (VIIa),
(VIIb), (VIIIa) (VIIIb), (IX), (IX'), (X), (X'), (XIa), (XIb), (XIIa) and
(XIIb) (hereunder also referred to as "(VIIa)-(XIIb)") as starting
materials.

[0074]From the viewpoint of facilitating synthesis and reaction of the
compounds represented by formulas (VIIa)-(XIIb), W1 and W2
preferably each independently represent a halogen atom or an alkyl
sulfonate group, aryl sulfonate group, arylalkyl sulfonate group, boric
acid ester residue, boric acid residue or trialkylstannyl group. When a
compound represented by formula (IX) or (X) is used as the starting
material, and its powerful electron-withdrawing property impedes
reaction, a compound represented by formula (IX') or (X') with the
carbonyl groups replaced by alkylenedioxy groups may be used as an
intermediate for reaction, and the alkylenedioxy groups subsequently
converted to carbonyl groups.

[0075]For example, a compound represented by formula (X') and a compound
represented by formula (XIIb) may be reacted to produce a compound
represented by the following formula (XIII) as an intermediate, and the
alkylenedioxy groups converted to carbonyl groups after the reaction to
produce a compound of the above formula (VI).

[0077]Examples of methods for producing the aforementioned conjugated
compounds include a method using Suzuki coupling reaction, a method using
Grignard reaction, a method using Stille reaction, a method using a Ni(0)
catalyst, a method using an oxidizing agent such as FeCl3, a method
using anionic oxidation reaction, a method using palladium acetate and an
organic base, a method involving preparation of a lithiated derivative
from an α-unsubstituted or halogenated compound, and oxidative
coupling, a method using electrochemical oxidation reaction, and a method
involving decomposition of an intermediate compound with an appropriate
leaving group.

[0078]Of these, method using Suzuki coupling reaction, method using
Grignard reaction, method using Stille reaction, method using Ni(0)
catalysts, method using anionic oxidation reaction and method using
palladium acetate and organic bases are preferred for easier structural
control, ready availability of the starting materials and simplification
of the reaction procedure.

[0079]Examples of the catalyst used for Suzuki coupling reaction include
tetrakis(triphenylphosphine)palladium or palladium acetate, and the
reaction may be carried out with addition of at least one equivalent and
preferably 1-10 equivalents of an inorganic base such as potassium
carbonate, sodium carbonate or barium hydroxide, an organic base such as
triethylamine or an inorganic salt such as cesium fluoride, with respect
to the monomer. The reaction may be carried out in a two-phase system,
with the inorganic salt in aqueous solution. The solvent used for the
reaction may be N,N-dimethylformamide, toluene, dimethoxyethane,
tetrahydrofuran or the like. The reaction temperature will depend on the
solvent used but is preferably about 50-160° C. The temperature
may be increased to near the boiling point of the solvent for reflux. The
reaction time will be between 1 hour and 200 hours. The Suzuki coupling
reaction is described in, for example, Chem. Rev. Vol. 95, p. 2457
(1995).

[0080]For reaction using a Ni(0) catalyst, it may include the method may
using a zerovalent nickel complex as the Ni(0) catalyst, and method of
producing zerovalent nickel in the system by reacting a nickel salt in
the presence of reducing agent. Examples of zerovalent nickel complexes
include bis(1,5-cyclooctadiene)nickel(0),
(ethylene)bis(triphenylphosphine)nickel(0) and
tetrakis(triphenylphosphine)nickel, among which
bis(1,5-cyclooctadiene)nickel(0) is preferred from the viewpoint of
general use and economy.

[0081]Addition of a neutral ligand during the reaction is also preferred
from the viewpoint of increasing the yield. A "neutral ligand" is a
ligand containing no anions or cations, and examples thereof include
nitrogen-containing ligands such as 2,2'-bipyridyl, 1,10-phenanthroline,
methylenebisoxazoline and N,N'-tetramethylethylenediamine; and tertiary
phosphine ligands such as triphenylphosphine, tritolylphosphine,
tributylphosphine and triphenoxyphosphine. Nitrogen-containing ligands
are preferred from the viewpoint of greater flexibility and lower cost,
while 2,2'-bipyridyl is especially preferred from the viewpoint of higher
reactivity and yield. For increased conjugated compound yield, a system
containing 2,2'-bipyridyl added as a neutral ligand to a system
containing bis(1,5-cyclooctadiene)nickel(0) is especially preferred. As
nickel salts to be used in the process for producing zerovalent nickel in
the system there may be mentioned nickel chloride and nickel acetate. As
reducing agents there may be mentioned zinc, sodium hydride, hydrazine
and their derivatives, and also lithium aluminum hydride. Ammonium
iodide, lithium iodide, potassium iodide and the like may also be used as
additives as necessary.

[0082]For Stille reaction, the catalyst used may be
tetrakis(triphenylphosphine)palladium or palladium acetate, and the
reaction may be conducted using an organic tin compound as monomer. The
solvent used for the reaction may be N,N-dimethylformamide, toluene,
dimethoxyethane, tetrahydrofuran or the like. The reaction temperature
will depend on the solvent used but is preferably about 50-160° C.
The temperature may be increased to near the boiling point of the solvent
for reflux. The reaction time will be between 1 hour and 200 hours.

[0083]For a method using anionic oxidation reaction, a halogen- or
hydrogen-substituted compound may be used as the monomer for reaction
with n-butyllithium to prepare a lithiated derivative, which is then
treated with an oxidizing agent such as copper(II) bromide, copper(II)
chloride, iron(III) acetylacetonate or the like. The solvent used for the
reaction may be toluene, dimethoxyethane, tetrahydrofuran, hexane,
heptane, octane or the like. The reaction temperature will depend on the
solvent used but is preferably about 50-160° C. The temperature
may be increased to near the boiling point of the solvent for reflux. The
reaction time will be between 5 minutes and 200 hours.

[0084]For a method using palladium acetate and an organic base, a
halogen-substituted compound may be used as the monomer and palladium(II)
acetate and an organic base such as diisopropylamine or triethylamine
added for reaction. The solvent used for the reaction may be
N,N-dimethylformamide, toluene, dimethoxyethane, tetrahydrofuran or the
like. The reaction temperature will depend on the solvent used but is
preferably about 50-160° C. The temperature may be increased to
near the boiling point of the solvent for reflux. The reaction time will
be between about 5 minutes and 200 hours.

[0085]When a conjugated compound of the present invention is to be used as
a material for an organic thin-film device, it is preferably subjected to
purification treatment by a method such as sublimation purification or
recrystallization, since the purity will affect the device
characteristics.

[0086]An organic thin film according to the present invention will now be
explained. The organic thin film of the present invention is one
comprising a conjugated compound as described above.

[0087]The organic thin film may be one comprising only one of the
aforementioned conjugated compounds, or it may include two or more of
such conjugated compounds. In order to enhance the electron transport and
hole transport properties of the organic thin film, a low molecular
compound or high molecular compound having an electron transport or hole
transport property (an electron transport material or hole transport
material) may also be combined in addition to the conjugated compound.

[0088]Any known hole transport material may be used, examples of which
include pyrazolines, arylamines, stilbenes, triaryldiamines,
oligothiophenes, polyvinylcarbazoles, polysilanes, polysiloxanes with
aromatic amines on the side chains or main chain, polyanilines,
polythiophenes, polypyrroles, polyarylenevinylenes and
polythienylenevinylenes, as well as derivatives of the foregoing.

[0089]Any known electron transport materials may also be used, examples of
which include metal complexes of oxadiazoles, quinodimethanes,
benzoquinones, naphthoquinones, anthraquinones,
tetracyanoanthraquinodimethanes, fluorenones, diphenyldicyanoethylenes,
diphenoquinones and 8-hydroxyquinolines, polyquinolines,
polyquinoxalines, polyfluorenes, C60 and other fullerenes, and
derivatives of the foregoing.

[0090]An organic thin film of the present invention may also contain a
charge generation material for generation of an electrical charge upon
absorption of light in the organic thin film. Any known charge generation
materials may be used, examples of which include azo compounds, diazo
compounds, ametallic phthalocyanine compounds, metal phthalocyanine
compounds, perylene compounds, polycyclic quinone-based compounds,
squarylium compounds, azulenium compounds, thiapyrylium compounds or
C60 and other fullerenes.

[0091]The organic thin film of the present invention may also contain
materials necessary for exhibiting various functions. Examples of such
materials include sensitizing agents to enhance the function of
generating charge by light absorption, stabilizers to increase stability,
and UV absorbers for absorption of UV light.

[0092]The organic thin film of the present invention may also contain high
molecular compound materials as macromolecular binders in addition to the
compounds mentioned above, in order to improve the mechanical properties.
It is preferable that the macromolecular binders are ones that do not
extremely interfere with the electron transport or hole transport
property, and ones does not have strong absorption for visible light.

[0094]There are no particular restrictions on the method for producing an
organic thin film of the present invention, and for example, there may be
used a method of film formation from a solution comprising the conjugated
compound and, as necessary, an electron transport or hole transport
material and a macromolecular binder and solvent in admixture therewith.
When the conjugated compound has sublimating property, it can be foamed
into a thin film by a vacuum vapor deposition method.

[0095]The solvent is not particularly restricted so long as it dissolves
the conjugated compound and the electron transport or hole transport
materials and macromolecular binders combined therewith.

[0096]Specific examples of such solvents include unsaturated
hydrocarbon-based solvents such as toluene, xylene, mesitylene, tetralin,
decalin, bicyclohexyl, n-butylbenzene, sec-butylbenzene and
tert-butylbenzene, halogenated saturated hydrocarbon-based solvents such
as carbon tetrachloride, chloroform, dichloromethane, dichloroethane,
chlorobutane, bromobutane, chloropentane, bromopentane, chlorohexane,
bromohexane, chlorocyclohexane and bromocyclohexane, halogenated
unsaturated hydrocarbon-based solvents such as chlorobenzene,
dichlorobenzene and trichlorobenzene, and ether-based solvents such as
tetrahydrofuran and tetrahydropyran. The conjugated compound of the
present invention can be dissolved in such solvents to at least 0.1% by
mass for most purposes, although this will differ depending on the
structure and molecular weight of the compound.

[0098]The film thickness of the organic thin film is preferably about 1
nm-100 μm, more preferably 2 nm-1000 nm, even more preferably 5 nm-500
nm and most preferably 20 nm-200 nm.

[0099]The step of producing the organic thin film of the present invention
may also include a step of orienting the conjugated compound. An organic
thin film having the conjugated compound oriented by such a step will
have the main chain molecules or side chain molecules aligned in a single
direction, thus improving the electron mobility or hole mobility.

[0100]The method of orienting the conjugated compound may be a known
method for orienting liquid crystals. Rubbing, photoorientation, shearing
(shear stress application) and pull-up coating methods are convenient,
useful and easy orienting methods, and rubbing and shearing are
preferred.

[0101]Since the organic thin film of the present invention has an electron
transport or hole transport property, by controlling the transport of
electrons or holes introduced from the electrode or charge generated by
photoabsorption, the organic thin film can be used in various organic
thin-film devices such as organic thin-film transistors or organic
photoelectric conversion devices (organic solar cells, optical sensors
and the like). When an organic thin film of the present invention is used
in such organic thin-film devices, it is preferably used after
orientation by orienting treatment in order to further enhance the
electron transport or hole transport property.

[0102]Application of an organic thin film of the present invention to an
organic thin-film transistor will now be explained. The organic thin-film
transistor may have a structure comprising a source electrode and drain
electrode, an organic thin-film layer (active layer) containing a
conjugated compound according to the present invention which is to act as
a current channel between them, and a gate electrode that is to control
the level of current flowing through the current channel, and examples of
the transistor include a field-effect type or static induction type.

[0103]A field-effect type organic thin-film transistor may comprise a
source electrode and drain electrode, an organic thin-film layer (active
layer) containing a conjugated compound according to the present
invention which is to act as a current channel between them, a gate
electrode that is to control the level of current flowing through the
current channel, and an insulating layer situated between the active
layer and the gate electrode. It is preferable that the source electrode
and drain electrode are provided in contact with the organic thin-film
layer (active layer) containing the conjugated compound of the present
invention, and the gate electrode is provided sandwiching the insulating
layer which is also in contact with the organic thin-film layer.

[0104]A static induction-type organic thin-film transistor comprises a
source electrode and drain electrode, an organic thin-film layer
containing a conjugated compound according to the present invention which
is to act as a current channel between them and a gate electrode that is
to control the level of current flowing through the current channel,
preferably with the gate electrode in the organic thin-film layer. Most
preferably, the source electrode, the drain electrode and the gate
electrode formed in the organic thin-film layer are provided in contact
with the organic thin-film layer containing the conjugated compound of
the present invention. The structure of the gate electrode may be any one
formed a current channel for flow from the source electrode to the drain
electrode, and that allows the level of current flowing through the
current channel to be controlled by the voltage applied to the gate
electrode; an example of such a structure is a combshaped electrode.

[0105]FIG. 1 is a schematic cross-sectional view of an organic thin-film
transistor (field-effect type organic thin-film transistor) according to
a first embodiment. The organic thin-film transistor 100 shown in FIG. 1
comprises a substrate 1, a source electrode 5 and drain electrode 6
formed at a prescribed spacing on the substrate 1, an active layer 2
formed on the substrate 1 covering the source electrode 5 and drain
electrode 6, an insulating layer 3 formed on the active layer 2, and a
gate electrode 4 formed on the insulating layer 3 covering the region of
the insulating layer 3 between the source electrode 5 and drain electrode
6.

[0106]FIG. 2 is a schematic cross-sectional view of an organic thin-film
transistor (field-effect type organic thin-film transistor) according to
a second embodiment. The organic thin-film transistor 110 shown in FIG. 2
comprises a substrate 1, a source electrode 5 formed on the substrate 1,
an active layer 2 formed on the substrate 1 covering the source electrode
5, a drain electrode 6 formed on the active layer 2 at a prescribed
spacing from the source electrode 5, an insulating layer 3 formed on the
active layer 2 and drain electrode 6, and a gate electrode 4 formed on
the insulating layer 3 covering the region of the insulating layer 3
between the source electrode 5 and drain electrode 6.

[0107]FIG. 3 is a schematic cross-sectional view of an organic thin-film
transistor (field-effect type organic thin-film transistor) according to
a third embodiment. The organic thin-film transistor 120 shown in FIG. 3
comprises a substrate 1, an active layer 2 formed on the substrate 1, a
source electrode 5 and drain electrode 6 formed at a prescribed spacing
on the active layer 2, an insulating layer 3 formed on the active layer 2
covering portions of the source electrode 5 and drain electrode 6, and a
gate electrode 4 formed on the insulating layer 3, covering a portion of
the region of the insulating layer 3 under which the source electrode 5
is formed and a portion of the region of the insulating layer 3 under
which the drain electrode 6 is formed.

[0108]FIG. 4 is a schematic cross-sectional view of an organic thin-film
transistor (field-effect type organic thin-film transistor) according to
a fourth embodiment. The organic thin-film transistor 130 shown in FIG. 4
comprises a substrate 1, a gate electrode 4 formed on the substrate 1, an
insulating layer 3 formed on the substrate 1 covering the gate electrode
4, a source electrode 5 and drain electrode 6 formed at a prescribed
spacing on the insulating layer 3 covering portions of the region of the
insulating layer 3 under which the gate electrode 4 is formed, and an
active layer 2 formed on the insulating layer 3 covering portions of the
source electrode 5 and drain electrode 6.

[0109]FIG. 5 is a schematic cross-sectional view of an organic thin-film
transistor (field-effect type organic thin-film transistor) according to
a fifth embodiment. The organic thin-film transistor 140 shown in FIG. 5
comprises a substrate 1, a gate electrode 4 formed on the substrate 1, an
insulating layer 3 formed on the substrate 1 covering the gate electrode
4, a source electrode 5 formed on the insulating layer 3 covering a
portion of the region of the insulating layer 3 under which the gate
electrode 4 is formed, an active layer 2 foamed on the insulating layer 3
covering a portion of the source electrode 5, and a drain electrode 6
formed on the insulating layer 3 at a prescribed spacing from the source
electrode 5 and covering a portion of the region of the active layer 2
under which the gate electrode 4 is formed.

[0110]FIG. 6 is a schematic cross-sectional view of an organic thin-film
transistor (field-effect type organic thin-film transistor) according to
a sixth embodiment. The organic thin-film transistor 150 shown in FIG. 6
comprises a substrate 1, a gate electrode 4 formed on the substrate 1, an
insulating layer 3 formed on the substrate 1 covering the gate electrode
4, an active layer 2 formed covering the region of the insulating layer 3
under which the gate electrode 4 is formed, a source electrode 5 formed
on the insulating layer 3 covering a portion of the region of the active
layer 2 under which the gate electrode 4 is formed, and a drain electrode
6 formed on the insulating layer 3 at a prescribed spacing from the
source electrode 5 and covering a portion of the region of the active
layer 2 under which the gate electrode 4 is formed.

[0111]FIG. 7 is a schematic cross-sectional view of an organic thin-film
transistor (static induction type organic thin-film transistor) according
to a seventh embodiment. The organic thin-film transistor 160 shown in
FIG. 7 comprises a substrate 1, a source electrode 5 formed on the
substrate 1, an active layer 2 formed on the source electrode 5, a
plurality of gate electrodes 4 formed at prescribed spacings on the
active layer 2, an active layer 2a formed on the active layer 2 covering
all of the gate electrodes 4 (the material composing the active layer 2a
may be the same as or different from that of the active layer 2), and a
drain electrode 6 formed on the active layer 2a.

[0112]In the organic thin-film transistors of the first to seventh
embodiments, the active layer 2 and/or the active layer 2a contains a
conjugated compound according to the present invention and forms a
current channel between the source electrode 5 and drain electrode 6. The
gate electrode 4 controls the level of current flowing through the
current channel of the active layer 2 and/or active layer 2a by
application of voltage.

[0113]This field-effect type organic thin-film transistor can be
manufactured by a publicly known process, such as the process described
in Japanese Unexamined Patent Publication HEI No. 5-110069, for example.
A static induction type organic thin-film transistor can also be
manufactured by a publicly known process such as the process described in
Japanese Unexamined Patent Publication No. 2004-006476, for example.

[0114]The material of the substrate 1 is not particularly restricted so
long as it does not inhibit the characteristics of the organic thin-film
transistor. The substrate 1 used may be a glass panel, flexible film
substrate or plastic panel.

[0115]Since organic solvent-soluble conjugated compounds are highly
advantageous and preferred in forming the active layer 2, by the organic
thin-film production method of the present invention described above,
organic thin films composed of the active layer 2 can be formed.

[0116]The insulating layer 3 in contact with the active layer 2 is not
particularly restricted so long as it is a material with high electrical
insulating properties, and any publicly known one may be used. Examples
include SiOx, SiNx, Ta2O5, polyimide, polyvinyl alcohol,
polyvinylphenol, organic glass and photoresists. From the viewpoint of
low voltage, it is preferred to use a material with high permittivity for
the insulating layer 3.

[0117]When the active layer 2 is formed on the insulating layer 3, it may
be formed after surface modification by treatment of the surface of the
insulating layer 3 with a surface treatment agent such as a silane
coupling agent in order to improve the interfacial properties between the
insulating layer 3 and active layer 2. Examples of surface treatment
agents include long-chain alkylchlorosilanes, long-chain
alkylalkoxysilanes, fluorinated alkylchlorosilanes, fluorinated
alkylalkoxysilanes and silylamine compounds such as hexamethyldisilazane.
Before treatment with the surface treatment agent, the insulating layer
surface may be pre-treated by ozone UV or O2 plasma.

[0118]After the organic thin-film transistor has been fabricated, in order
to protect the device it is preferable that a protecting film is formed
on the organic thin-film transistor. This will help prevent reduction in
the characteristics of the organic thin-film transistor due to shielding
from air. A protecting film can also minimize adverse effects from the
step of forming an operating display device on the organic thin-film
transistor.

[0119]Examples of the method of forming the protecting film include
covering with a UV curing resin, thermosetting resin, inorganic SiONx
film or the like. For effective shielding from air, the steps after
fabrication of the organic thin-film transistor and before formation of
the protecting film are preferably carried out without exposure to air
(for example, in a dry nitrogen atmosphere or in a vacuum).

[0120]Application of an organic thin film of the present invention in a
photoelectric conversion device will now be explained. A solar cell or
optical sensor is typical photoelectric conversion device. FIG. 8 is a
schematic cross-sectional view of a solar cell according to an
embodiment. The solar cell 200 shown in FIG. 8 comprises a substrate 1, a
first electrode 7a formed on the substrate 1, an active layer 2 made of
an organic thin film that contains a conjugated compound of the present
invention formed on the first electrode 7a, and a second electrode 7b
formed on the active layer 2.

[0121]In this solar cell 200, a transparent or semi-transparent electrode
is used for either the first electrode 7a or the second electrode 7b. As
electrode materials there may be used metals such as aluminum, gold,
silver, copper, alkali metal and alkaline earth metals or their
semi-transparent films, or transparent conductive films. In order to
obtain high open voltage, it is preferred to select the electrodes so as
to produce a large work function difference. Charge generators,
sensitizing agents and the like may also be added in order to increase
photosensitivity in the active layer 2 (organic thin film). The substrate
1 may be a silicon substrate, glass panel, plastic panel or the like.

[0122]FIG. 9 is a schematic cross-sectional view of an optical sensor
according to a first embodiment. The optical sensor 300 shown in FIG. 9
comprises a substrate 1, a first electrode 7a formed on the substrate 1,
an active layer 2 made of an organic thin film comprising a conjugated
compound of the present invention, formed on the first electrode 7a, a
charge generation layer 8 formed on the active layer 2, and a second
electrode 7b formed on the charge generation layer 8.

[0123]FIG. 10 is a schematic cross-sectional view of an optical sensor
according to a second embodiment. The optical sensor 310 shown in FIG. 10
comprises a substrate 1, a first electrode 7a formed on the substrate 1,
a charge generation layer 8 formed on the first electrode 7a, an active
layer 2 made of an organic thin film comprising a conjugated compound of
the present invention, formed on the charge generation layer 8, and a
second electrode 7b formed on the active layer 2.

[0124]FIG. 11 is a schematic cross-sectional view of an optical sensor
according to a third embodiment. The optical sensor 320 shown in FIG. 11
comprises a substrate 1, a first electrode 7a formed on the substrate 1,
an active layer 2 made of an organic thin film that comprises a
conjugated compound of the present invention, formed on the first
electrode 7a, and a second electrode 7b formed on the active layer 2.

[0125]In the optical sensors of the first to third embodiments, a
transparent or semi-transparent electrode is used for either or both the
first electrode 7a or the second electrode 7b. The charge generation
layer 8 is a layer that generates an electrical charge upon absorption of
light. As electrode materials there may be used metals such as aluminum,
gold, silver, copper, alkali metal and alkaline earth metals or their
semi-transparent films, or transparent conductive films. Carrier
generators, sensitizing agents and the like may also be added in order to
increase photosensitivity in the active layer 2 (organic thin film). The
substrate 1 may be a silicon substrate, glass panel, plastic panel or the
like.

[0126]The present invention was explained above in detail based on
embodiments thereof. However, the present invention is not limited to
these described embodiments. The present invention may also be applied in
a variety of modifications so long as the gist thereof is maintained.

[0127]The second invention group will now be explained in detail.

[0128]The nitrogen-containing fused-ring compound of the present invention
has a structure represented by the above formula (α-I).

[0129]In the above formula (α-I), R21 and R22 each
independently represent a hydrogen atom, a halogen atom or an optionally
substituted monovalent group, and Z21 and Z22 each
independently represent any one of the groups represented by the above
formulas (α-i)-(α-ix). Also, R23, R24, R25 and
R26 each independently represent a hydrogen atom, a halogen atom or
a monovalent group, and R23 and R24 may bond together to form a
ring. The left side and the right side of the group represented by the
above formula (α-viii) may be interchanged. From the viewpoint of
facilitating production, Z21 and Z22 preferably have the same
structure.

[0130]The nitrogen-containing fused-ring compound of the present invention
represented by the above formula (α-I) is preferably a compound
represented by the following formula (α-I-I).

##STR00021##

[0131]In the above formula (α-I-I), Z21, Z22 and Z1'
each independently represents any one of the groups represented by the
above formulas (α-i)-(α-ix). Also, R1 and R2 have
the same definitions as R1 and R2 in formula (I), and each
independently represent a hydrogen atom, a halogen atom or a monovalent
group. Specific examples of halogen atoms and monovalent groups include
the same ones as for R1 and R2 in the above formula (I). Also,
R0 has the same definition as R0 in the above formula (III),
and it represents a hydrogen atom, a C1 to C20 alkyl group or a C1 to C20
alkoxy group. A plurality the groups in R0 may be the same or
different. Specific examples of a C1 to C20 alkyl group and a C1 to C20
alkoxy group there may be mentioned the same ones as for R0 in the
above formula (III).

[0132]In the nitrogen-containing fused-ring compound of the present
invention, it is preferable that at least one of R21 and R22 in
the above formula (α-I) is a group represented by the following
formula (IV), and more preferable that both R21 and R22 are
groups represented by the following formula (IV).

##STR00022##

[0133]The group represented by the above formula (IV) is a group with the
same definition as the group represented by the above formula (IV)
explained above for the first invention group, where R10 represents
a hydrogen atom, a fluorine atom, a C1 to C20 alkyl group, a C1 to C20
fluoroalkyl group, a C1 to C20 alkoxy group or a C1 to C20 fluoroalkoxy
group, Z2 represents a group represented by any one of the following
formulas (xi)-(xix), R13, R14, R15 and R16 each
independently represent a hydrogen atom, a halogen atom or a monovalent
group, and R13 and R14 may bond together to form a ring.
Specific examples of a C1-20 alkyl, a C1 to C20 fluoroalkyl group, a C1
to C20 alkoxy group and a C1 to C20 fluoroalkoxy group include the same
one mentioned above for the first invention group.

##STR00023##

[0134]The nitrogen-containing fused-ring polymer of the present invention
has a repeating unit represented by the above formula (α-II). That
is, a nitrogen-containing fused-ring polymer of the present invention has
at least one and preferably 2 or more repeating units represented by the
above formula (α-II), and may additionally have another repeating
unit.

[0135]In the above formula (α-II), Z21 and Z22 each
independently represent any one of the group represented by the above
formulas (α-i)-(α-ix). R23, R24, R25 and
R26 each independently represent a hydrogen atom, a halogen atom or
a monovalent group, and R23 and R24 may bond together to form a
ring. The left side and the right side of the group represented by the
above formula (α-viii) may be interchanged. By having such a
repeating unit, the compound can be used as an organic n-type
semiconductor with a particularly excellent electron transport property.

[0136]It is preferable that the nitrogen-containing fused-ring polymer of
the present invention preferably has at least one repeating unit
represented by the above formula (α-II) and at least one repeating
unit represented by the following formula (α-III) which is
different from the repeating unit represented by the above formula
(α-II). It is more preferable that it has at least one repeating
unit represented by the above formula (α-II) and at least one
repeating unit represented by the following formula (α-IV). Such a
structure will widen the range of variability for the soluble,
mechanical, thermal and electronic characteristics. In the following
formula (α-III), Ar21 represents a divalent aromatic
hydrocarbon or a divalent heterocyclic group, wherein the groups may be
optionally substituted. The ratio of the repeating unit represented by
formula (α-II) and the repeating unit represented by formula
(α-III) (preferably the repeating unit represented by the following
formula (α-IV)) is preferably 10-1000 mol of the latter to 100 mol
of the former, more preferably 25-400 mol of the latter to 100 mol of the
former and even more preferably 50-200 mol of the latter to 100 mol of
the former.

[Chemical Formula 42]

Ar21 (α-III)

[0137]In this case, Ar21 is preferably a repeating unit represented
by the following formula (α-IV). In the formula, Z23 is the
same as or different from Z21 or Z22, and is any one of the
groups represented by the above formulas (α-i)-(α-ix). Also,
R27 and R28 each independently represents a hydrogen atom, a
halogen atom or a monovalent group, and R27 and R28 may bond
together to form a ring. R23, R24, R25 and R26 have
the same definitions as above.

##STR00024##

[0138]The divalent aromatic hydrocarbon group represented by Ar21 is
an atomic group remaining after removing two hydrogen atoms from a
benzene ring or fused ring, and they will generally have 6-60 and
preferably 6-20 carbon atoms. Examples of fused rings include
naphthalene, anthracene, tetracene, pentacene, pyrene, perylene and
fluorene rings. As divalent aromatic hydrocarbon groups there are
preferred atomic groups remaining after removing two hydrogens from a
benzene ring, pentacene ring, pyrene ring or fluorene ring. The divalent
aromatic hydrocarbon groups may be optionally substituted. The numbers of
carbon atoms of the substituents are not included in the number of carbon
atoms in the divalent aromatic hydrocarbon groups. As substituents there
may be mentioned halogen atoms and saturated or unsaturated hydrocarbon,
aryl, alkoxy, aryloxy, monovalent heterocyclic, amino, nitro and cyano
groups.

[0139]The divalent heterocyclic group represented by Ar21 is an
atomic group remaining after removing two hydrogen atoms from a
heterocyclic compound, and the number of carbon atoms will normally be
3-60 and preferably 3-20. Examples of divalent heterocyclic groups
include atomic groups remaining after removing two hydrogen atoms from
thiophene, thienothiophene, dithienothiophene, thiazole, pyrrole,
pyridine or pyrimidine, and preferred are atomic groups remaining after
removing two hydrogens from thiophene, thienothiophene or thiazole. The
divalent heterocyclic group may have substituents, and the numbers of
carbons of the substituents are not included in the number of carbons in
the divalent heterocyclic group. As substituents there may be mentioned
halogen atoms and saturated or unsaturated hydrocarbon groups, aryl
groups, alkoxy groups, aryloxy groups, monovalent heterocyclic groups,
amino groups, nitro groups and cyano groups.

[0140]A heterocyclic compound referred to here is an organic compound with
a ring structure, the elements composing the ring of which include not
only carbon but also heteroatoms such as oxygen, sulfur, nitrogen,
phosphorus, boron and silicon.

[0141]Examples of Z21 and Z22 in formula (α-I) are
preferably include groups represented by the above formulas (α-i),
(α-ii), (α-iii), (α-vii), (α-viii) and
(α-ix), preferably groups represented by formulas the (α-ii)
and (α-vii), and most preferably groups represented by formula the
(α-ii). Z23 in formula (α-IV) is preferably, for
example, a group represented by formula the above (α-i),
(α-ii), (α-iii), (α-vii), (α-viii) or
(α-ix), preferably a group represented by formula (α-ii),
(α-iii), (α-vii) or (α-ix), and most preferably a group
represented by formula (α-ii). Thiazole rings, oxazole rings and
imidazole rings, and especially thiazole rings, have a characteristic
electrical nature and exhibit various electrical properties.

[0142]In formulas (α-vii), (α-viii) and (α-ix), and
formulas (α-I), (α-II) and (α-IV), R21-R28
each independently represent a hydrogen atom, a halogen atom or a
monovalent group, and a ring may be formed between R23 and R24
and between R27 and R28.

[0143]It is preferable that monovalent groups represented by
R21-R28 are straight-chain or branched low molecular chains,
monovalent cyclic groups, wherein the cyclic groups may have monocycles
or fused rings, hydrocarbon rings or heterocyclic rings, saturated or
unsaturated, and with or without substituents. A monovalent group may be
an electron-donating group or electron-withdrawing group.

[0144]It is more preferable that monovalent groups represented by
R21-R28 are straight-chain or branched low molecular chains (C1
to C20 groups), monovalent cyclic groups with 3-60 annular atoms, wherein
cyclic groups may have monocycles or fused rings, hydrocarbon rings or
heterocyclic rings, saturated or unsaturated, and with or without
substituents, saturated or unsaturated hydrocarbon groups, hydroxyl
groups, alkoxy groups, alkanoyloxy groups, amino groups, oxyamino groups,
alkylamino groups, dialkylamino groups, alkanoylamino groups, cyano
groups, nitro groups, sulfo groups, alkyl groups optionally substituted
with one or more halogen atoms, alkoxysulfonyl groups, wherein some or
all of the hydrogen atoms in the alkoxy groups may be optionally
substituted with one or more halogen atoms, alkylsulfonyl groups, wherein
some or all of the hydrogen atoms in the alkyl groups may be optionally
substituted with one or more halogen atoms, sulfamoyl groups,
alkylsulfamoyl groups, carboxyl groups, carbamoyl groups, alkylcarbamoyl
groups, alkanoyl groups, wherein some or all of the hydrogen atoms in the
alkanoyl groups may be optionally substituted with one or more halogen
atoms, and alkoxycarbonyl groups. Examples of monovalent cyclic groups
with 3-60 annular atoms include groups represented by the following
formulas.

##STR00025##

[0145]As halogen atoms for the purpose of the present specification there
may be mentioned a fluorine atom, a chlorine atom, a bromine atom and an
iodine atom.

[0146]Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl,
n-butyl, isobutyl, sec-butyl and tert-butyl, and this also applies for
groups containing alkyl groups in their structures (such as alkoxy,
alkylamino group and alkoxycarbonyl). It is preferable that alkyl groups
are C1 to C12 alkyl groups, and more preferable that they are C1 to C10
alkyl groups.

[0148]Examples of alkanoyl groups include formyl groups, acetyl groups,
propionyl groups, isobutyryl groups, valeryl groups and isovaleryl
groups, and this also applies for groups containing alkanoyl groups in
their structures (such as alkanoyloxy and alkanoylamino). A "C1 alkanoyl
group" is formyl, which also applies for groups containing alkanoyl
groups in their structures. As preferred alkanoyl groups there may be
mentioned formyl and acetyl.

[0149]R23 and R24 in formula (α-vii) mentioned for
formulas (α-I), (α-II) and (α-IV) are preferably
hydrogen atoms, fluorine atoms, alkyl groups or alkoxy groups, and more
preferably each is hydrogen atom or fluorine atom.

[0150]Either or both R21 and R22 in the above formula
(α-I) preferably have one or more hydrogen atoms in the
substituent-containing groups replaced with fluorine atoms, and
preferably either or both have a carbonyl structure. More preferably,
R21 and R22 have carbonyl structures and have a group with one
or more hydrogen atoms replaced with fluorine atoms. Such a group will
lower the LUMO level and improve the solubility in organic solvents. From
the viewpoint of increasing the electron transport property, more
preferably either or both R21 and R22 groups having
fluoroalkyl, fluoroalkoxy, fluoroaryl or α-fluoroketone structures,
fluoroalkyl-substituted aryl groups, fluoroalkoxy-substituted aryl
groups, aryl groups substituted with groups having α-fluoroketone
structures, fluoroalkyl-substituted monovalent heterocyclic groups,
fluoroalkoxy-substituted monovalent heterocyclic groups or monovalent
heterocyclic groups substituted with groups having α-fluoroketone
structures, and most preferably both R21 and R22 are groups
having fluoroalkyl, fluoroalkoxy, fluoroaryl or α-fluoroketone
structures, fluoroalkyl-substituted aryl groups, fluoroalkoxy-substituted
aryl groups, aryl groups substituted with groups having
α-fluoroketone structures, fluoroalkyl-substituted monovalent
heterocyclic groups, fluoroalkoxy-substituted monovalent heterocyclic
groups or monovalent heterocyclic groups substituted with groups having
α-fluoroketone structures.

[0151]It is sufficient if the nitrogen-containing fused-ring polymer of
the present invention has a repeating unit represented by the above
formula (α-II), and it may have two or more repeating units
represented by formula (α-II). In addition to the repeating unit
represented by formula (α-II) it may also have a unit represented
by the above formula (α-III), or two or more units represented by
formula (α-III).

[0152]It is preferable that the nitrogen-containing fused-ring polymer of
the present invention has a structure wherein a repeating unit
represented by the above formula (α-II) and a repeating unit
represented by the above formula (α-III) (preferably a repeating
unit represented by the above formula (α-IV)) are adjacent. When a
repeating unit represented by the above formula (α-II) is adjacent
to a repeating unit represented by the above formula (α-III)
(preferably a repeating unit represented by the above formula
(α-IV)), because it is possible to reduce the torsional angle
between the adjacent aromatic rings or heterocyclic rings, thus improving
the intramolecular twist, widening the intramolecular π conjugation
and lowering the LUMO level, it is possible to enhance the electron
transport property as a result. The "torsional angle" mentioned here is
defined as the angle between 0 and 90 degrees among the angles formed by
the plane containing the heterocyclic ring in the repeating unit
represented by formula (α-II), and the plane containing the
adjacently bonded aromatic ring or heterocyclic ring. When a repeating
unit represented by the above formula (α-II) is adjacent to a
repeating unit represented by the above formula (α-III) (preferably
a repeating unit represented by the above formula (α-IV)), the
torsional angle will usually be 0-45 degrees, typically 0-40 degrees and
more typically 0-30 degrees.

[0153]FIG. 12 is a drawing showing the torsional angle formed between the
ring of a repeating unit represented by formula (α-II) and the ring
of a repeating unit represented by formula (α-IV). The torsional
angle in FIG. 12 is the angle formed between the plane of
N--C1--C4 and the plane of C1--C4--C5.

[0154]The nitrogen-containing fused-ring polymer of the present invention
is preferably represented by the following formula (α-V) or
(α-VI) from the viewpoint of increasing the electron transport
property.

##STR00026##

[0155]Here, Z21, Z22 and Ar21 have the same definitions as
above. When a plurality of the groups in Z21, Z22 and Ar21
are present, they may be the same or different. The symbol k2 represents
an integer of 1-10, preferably 1-6 and even more preferably 1-3. The
symbol m2 represents an integer of 2-500, preferably 2-100 and even more
preferably 3-20. The symbol n2 represents an integer of 1-500, preferably
1-100 and even more preferably 2-20. Particularly preferred among these
are compounds wherein Z21 and Z22 are all of formula
(α-ii).

[0156]When the end groups of the nitrogen-containing fused-ring polymer
has polymerizing active groups, these may be used as precursors for the
nitrogen-containing fused-ring polymer. In this case, the
nitrogen-containing fused-ring polymer preferably has at least two
polymerizing active groups in the molecule. Examples of polymerizing
active groups include halogen atoms, and alkyl sulfonate, aryl sulfonate,
arylalkyl sulfonate, alkylstannyl, arylstannyl, arylalkylstannyl, boric
acid ester residue, sulfoniummethyl, phosphoniummethyl,
phosphonatemethyl, monohalogenated methyl, boric acid residue
(--B(OH)2), formyl and vinyl groups, among which halogen atoms,
alkylstannyl groups and boric acid ester residue groups are preferred.
Examples of boric acid ester residues include groups represented by the
following formula.

##STR00027##

[0157]When a nitrogen-containing fused-ring polymer of the present
invention is to be used as an organic thin film and polymerizing active
groups remain at the ends, they are preferably protected with stable
groups to avoid potential reduction in the characteristics and durability
of devices formed therefrom.

[0158]As end groups there may be mentioned hydrogen atoms, fluorine atoms,
alkyl groups, alkoxy groups, acyl groups, aminoketo groups, aryl groups,
heterocyclic groups, wherein some or all of the hydrogen atoms bonded to
the groups are optionally replaced with fluorine), groups with
α-fluoroketone structures and electron-donating or
electron-withdrawing groups, and from the viewpoint of increasing the
electron transport property there are preferred fluoroalkyl groups,
fluoroalkoxy groups, fluoroaryl groups, groups with α-fluoroketone
structures and electron-withdrawing groups, and there are more preferred
groups wherein all of the hydrogen atoms are replaced with fluorine
atoms, such as perfluoroalkyl groups, perfluoroalkoxy groups or
perfluorophenyl groups. It is preferable that they have conjugated bonds
that are continuous with the conjugated structure of the main chain, and
Example of the structure may include the structure bonding with aryl or
heterocyclic groups via carbon-carbon bonds.

[0159]Examples of most preferred among the nitrogen-containing fused-ring
polymers of the present invention are represented by the following
formulas (α-1)-(α-5), for example.

##STR00028##

[0160]Here, R29 and R30 represent end groups, which may be the
same or different, examples of which include the end groups mentioned
above, preferably fluoroalkyl groups and groups with α-fluoroketone
structures and more preferably perfluoroalkyl groups and groups with
α-fluoroketone structures. R31, R32, R33 and
R34 each independently represent a hydrogen atom or an arbitrary
substituent, being preferably alkyl group, alkoxy group or aryl group and
more preferably alkyl group. A plurality of the groups in R31,
R32, R33 and R34 in the nitrogen-containing fused-ring
polymer may be the same or different. In order to facilitate production,
a plurality of the groups in R31, R32, R33 and R34
groups are preferably the same. The group for q2 may be appropriately
selected according to the method for forming the organic thin film using
the nitrogen-containing fused-ring polymer. If the nitrogen-containing
fused-ring polymer has sublimating property, a vapor growth process such
as vacuum vapor deposition may be used to form the organic thin film, in
which case q2 is an integer of preferably 1-10, more preferably 2-10 and
even more preferably 2-5. On the other hand, when the organic thin film
is to be formed using a method of coating a solution of the
nitrogen-containing fused-ring polymer dissolved in an organic solvent,
q2 is an integer of preferably 3-500, more preferably 6-300 and even more
preferably 20-200. When the film is formed by coating, from the viewpoint
of homogeneity of the film, it is preferable that the number-average
molecular weight of the nitrogen-containing fused-ring polymer based on
polystyrene is between 1×103 and 1×107 and more
preferable that it is between 1×104 and 1×106.

[0161]The following may be mentioned as specific examples of
nitrogen-containing fused-ring compounds and nitrogen-containing
fused-ring polymers of the present invention.

##STR00029## ##STR00030##

[0162]In the formulas, n2 represents the polymerization degree.

[0163]The nitrogen-containing fused-ring compounds or nitrogen-containing
fused-ring polymers of the present invention may be produced by any
method, but it is preferable that they are produced by the production
method described below.

[0164]A method for producing a nitrogen-containing fused-ring compound of
the present invention will be explained first. The nitrogen-containing
fused-ring compound (α-d) represented by the above formula
(α-I) can be produced by a process shown in the following scheme,
for example, in which a precursor (α-b) is first produced using a
starting material represented by the following formula (α-a) or
(α-a') and then the precursor (α-b) is reacted with a
carbonyl crosslinking agent. Different substituents can also be
introduced by a production method including a step obtaining compound
(α-f). The protecting group of the compound (α-j) may be
removed afterward to obtain a carbonyl compound.

##STR00031##

[0165]Here, Z21 and Z22 have the same definitions as above,
R20 has the same definition as R21, and a plurality of the
groups in R20 may be the same or different. V20, V20' and
V20'' represent reactive groups which may be the same or different,
and specifically they represent halogen atoms, alkyl sulfonate groups,
aryl sulfonate groups, arylalkyl sulfonate groups, alkylstannyl groups,
arylstannyl groups, arylalkylstannyl groups, boric acid ester residue,
sulfoniummethyl groups, phosphoniummethyl groups, phosphonatemethyl
groups, monohalogenated methyl groups, boric acid residue, formyl or
vinyl groups.

[0167]X20 and X20' represent halogen atoms and Y20,
Y20' and Y20'' each independently represents leaving groups,
examples of which include amino groups and alkoxy groups.

[0168]At the reaction process described above, in order to protect the
highly reactive functional groups, if necessary, the process may further
include a step of subsequently converting the highly reactive functional
groups to inactive functional groups (protecting groups) to protect them
if necessary, and a step of removing the protecting groups upon
completion of the reaction. Protecting groups may be appropriately
selected according to the functional groups to be protected and the
reaction employed, and preferred examples include trimethylsilyl (TMS),
triethylsilyl (TES), tert-butyldimethylsilyl (IBS or TBDMS),
triisopropylsilyl (UPS) and tert-butyldiphenylsilyl (TBDPS) for
protection of active hydrogens.

[0169]A solvent may also be appropriately used as necessary in the
reaction step described above. It is most preferable that the solvent
used is one that does not interfere with the desired reaction, and
examples include aliphatic hydrocarbons such as hexane, aromatic
hydrocarbons such as benzene and toluene, nitriles such as acetonitrile,
ethers such as diethyl ether, tetrahydrofuran and 1,2-dimethoxyethane,
and halogenated solvents such as dichloromethane, 1,2-dichloroethane and
carbon tetrachloride. These may be used alone or in combinations of two
or more. An example of a suitable solvent is dichloromethane.

[0170]When a nitrogen-containing fused-ring compound of the present
invention is to be used as a material for an organic thin-film device,
since the purity will affect the device characteristics, the produced
compound is preferably subjected to purification treatment by a method
such as distillation, sublimation purification or recrystallization.

[0171]The reaction conditions and reaction reagents for the production
method may also be appropriately selected among others than those
mentioned above. It is preferable that the nitrogen-containing fused-ring
compounds of the present invention represented by the above formula
(α-I) are produced by the production method of the present
invention as mentioned above, but this is not limitative and they may be
produced by other methods as well.

[0172]A method for producing a nitrogen-containing fused-ring polymer of
the present invention will now be explained. Nitrogen-containing
fused-ring polymers of the present invention can be produced using
compounds represented by the following formulas
(α-VII)-(α-IX), for example, as starting materials and
reacting them.

[0175]Examples of reaction methods to be used for production of a
nitrogen-containing fused-ring polymer of the present invention, include
a method of using Wittig reaction, a method of using Heck reaction, a
method of using Horner-Wadsworth-Emmons reaction, a method of using
Knoevenagel reaction, a method of using Suzuki coupling reaction, a
method of using Grignard reaction, a method of using Stifle reaction, a
method of using Ni(0) catalyst, a method of using oxidizing agents such
as FeCl3, a method of using electrochemical oxidation reaction, and
a method involving decomposition of an intermediate compound with an
appropriate leaving group.

[0176]Of the methods mentioned above, there are preferred a method of
using Wittig reaction, a method of using Heck reaction, a method of using
Horner-Wadsworth-Emmons reaction, a method of using Knoevenagel reaction,
a method of using Suzuki coupling reaction, a method of using Grignard
reaction, a method of using Stille reaction and a method of using Ni(0)
catalyst polymerization, for easier structural control. Also, a method of
using Suzuki coupling reaction, a method of using Grignard reaction, a
method of using Stille reaction and a method of using Ni(0) catalysts are
preferred for ready availability of starting materials and simplification
of the reaction procedure.

[0177]The monomer (compound represented by any one of the above formulas
(α-VII)-(α-IX)) may be dissolved in an organic solvent if
necessary and reacted between the melting point and boiling point of the
organic solvent using an alkali or appropriate catalyst, for example.

[0178]The organic solvent used will differ depending on the compounds and
reaction used, but in order to limit secondary reactions, it is
preferable that the solvent is one that has been sufficiently
deoxygenated and allows the reaction to proceed in an inert atmosphere.
Similarly, dehydration treatment is also preferably carried out (except
cases of reaction conducted in a two-phase system with water, such as the
Suzuki coupling reaction).

[0179]An appropriate alkali or catalyst is added for the reaction. These
may be selected as appropriate for the reaction used. It is preferable
that the alkali or catalyst is one that thoroughly dissolves in the
solvent used for the reaction.

[0180]When a nitrogen-containing fused-ring polymer of the present
invention is to be used as a material for an organic thin-film device,
since the purity will affect the device characteristics, the monomer is
preferably polymerized after purification by a method such as
distillation, subliming purification or recrystallization. After
synthesis of the nitrogen-containing fused-ring polymer, it is preferably
subjected to purifying treatment such as separation by reprecipitation or
chromatography.

[0181]Examples of solvents to be used for the reaction include saturated
hydrocarbons such as pentane, hexane, heptane, octane and cyclohexane,
unsaturated hydrocarbons such as benzene, toluene, ethylbenzene and
xylene, halogenated saturated hydrocarbons such as carbon tetrachloride,
chloroform, dichloromethane, chlorobutane, bromobutane, chloropentane,
bromopentane, chlorohexane, bromohexane, chlorocyclohexane and
bromocyclohexane, halogenated unsaturated hydrocarbons such as
chlorobenzene, dichlorobenzene and trichlorobenzene, alcohols such as
methanol, ethanol, propanol, isopropanol, butanol and t-butyl alcohol,
carboxylic acids such as formic acid, acetic acid and propionic acid,
ethers such as dimethyl ether, diethyl ether, methyl-t-butyl ether,
tetrahydrofuran, tetrahydropyran and dioxane, and inorganic acids such as
hydrochloric acid, hydrobromic acid, hydrofluoric acid, sulfuric acid and
nitric acid. A single solvent may be used alone or two or more may be
used in combination.

[0182]The reaction may be followed by ordinary post-treatment such as, for
example, quenching with water, subsequent extraction with an organic
solvent and distillation of the solvent. Isolation and purification of
the product can be carried out by chromatographic fractionation or
recrystallization.

[0183]An organic thin film according to the present invention will now be
explained. The organic thin film of the present invention comprises a
nitrogen-containing fused-ring compound and/or nitrogen-containing
fused-ring polymer of the present invention (hereunder collectively
referred to as "nitrogen-containing compound of the present invention").

[0184]The film thickness of the organic thin film will usually be about 1
nm-100 μm, preferably 2 nm-1000 nm, even more preferably 5 nm-500 nm
and most preferably 20 nm-200 nm.

[0185]The organic thin film may comprise a single nitrogen-containing
compound of the present invention, or it may comprise two or more
nitrogen-containing compounds of the present invention. In order to
enhance the electron transport and hole transport properties of the
organic thin film, a low molecular compound or high molecular compound
having an electron transport or hole transport property may also be
combined with the nitrogen-containing compound of the present invention.

[0186]Any known hole transport material may be used, examples of which
include pyrazoline derivatives, arylamine derivatives, stilbene
derivatives, triaryldiamine derivatives, oligothiophene and its
derivatives, polyvinylcarbazole and its derivatives, polysilane and its
derivatives, polysiloxane derivatives having aromatic amines on the side
chains or main chains, polyaniline and its derivatives, polythiophene and
its derivatives, polypyrrole and its derivatives, polyarylenevinylene and
its derivatives or polythienylenevinylene and its derivatives, and any
known electron transport materials may also be used, examples of which
include oxadiazole derivatives, quinodimethane and its derivatives,
benzoquinone and its derivatives, naphthoquinone and its derivatives,
anthraquinone and its derivatives, tetracyanoanthraquinodirnethane and
its derivatives, fluorenone derivatives, diphenyldicyanoethylene and its
derivatives, diphenoquinone derivatives, metal complexes of
8-hydroxyquinoline and its derivatives, polyquinoline and its
derivatives, polyquinoxaline and its derivatives, polyfluorene and its
derivatives, and C60 fullerenes and their derivatives.

[0187]An organic thin film of the present invention may also contain a
charge generation material for generation of an electrical charge upon
absorption of light in the organic thin film. Any known charge generation
materials may be used, examples of which include azo compounds and their
derivatives, diazo compounds and their derivatives, ametallic
phthalocyanine compounds and their derivatives, metallic phthalocyanine
compounds and their derivatives, perylene compounds and their
derivatives, polycyclic quinone-based compounds and their derivatives,
squarylium compounds and their derivatives, azulenium compounds and their
derivatives, thiapyrylium compounds and their derivatives, and C60
fullerenes and their derivatives.

[0188]The organic thin film of the present invention may also contain
materials necessary for exhibiting various functions. Examples include
sensitizing agents to enhance the function of generating charge by light
absorption, stabilizers to increase stability, and UV absorbers for
absorption of UV light.

[0189]The organic thin film of the present invention may also contain high
molecular compound materials as macromolecular binders in addition to the
nitrogen-containing compound of the present invention, in order to
improve the mechanical properties. It is preferable that as
macromolecular binders ones that do not extremely interfere with the
electron transport or hole transport property, and ones that do not have
strong absorption for visible are used.

[0190]Examples of such macromolecular binders include
poly(N-vinylcarbazole), polyanilines and their derivatives,
polythiophenes and their derivatives, poly(p-phenylenevinylene) and its
derivatives, poly(2,5-thienylenevinylene) and its derivatives,
polycarbonates, polyacrylates, polymethyl acrylate, polymethyl
methacrylate, polystyrene, polyvinyl chloride, polysiloxanes and the
like.

[0191]The method for producing the organic thin film of the present
invention may be, for example, a method of forming a film from a solution
comprising the nitrogen-containing compound of the present invention,
with an electron transport material or hole transport material and
macromolecular binder as necessary. When the nitrogen-containing compound
of the present invention has a sublimating property, the thin film may be
formed by vacuum vapor deposition.

[0192]The solvent used to form the film from the solution may be any one
that dissolves the nitrogen-containing compound of the present invention
and the electron transport material or hole transport material and
macromolecular binder combined therewith.

[0193]Examples of solvents to be used for formation of the organic thin
film of the present invention from a solution include unsaturated
hydrocarbon-based solvents such as toluene, xylene, mesitylene, tetralin,
decalin, bicyclohexyl, n-butylbenzene, sec-butylbenzene and
tert-butylbenzene, halogenated saturated hydrocarbon-based solvents such
as carbon tetrachloride, chloroform, dichloromethane, dichloroethane,
chlorobutane, bromobutane, chloropentane, bromopentane, chlorohexane,
bromohexane, chlorocyclohexane and bromocyclohexane, halogenated
unsaturated hydrocarbon-based solvents such as chlorobenzene,
dichlorobenzene and trichlorobenzene, and ether-based solvents such as
tetrahydrofuran and tetrahydropyran. Dissolution in these solvents will
usually be to 0.1% by mass or greater, although this will depend on the
structure and molecular weight of the nitrogen-containing compound of the
present invention.

[0195]The steps for producing the organic thin film of the present
invention may include a step of orienting the nitrogen-containing
compound of the present invention. An organic thin film with the
nitrogen-containing compound oriented by such a step will have the main
chain molecules or side chain molecules aligned in a single direction,
thus improving the electron mobility or hole mobility.

[0196]The method for orienting the nitrogen-containing compound may be any
method known for orientation of liquid crystals. Rubbing,
photoorientation, shearing (shear stress application) and pull-up coating
methods are convenient, useful and easy orienting methods, and rubbing
and shearing are preferred.

[0197]The steps for production of the organic thin film of the present
invention may further include a step of annealing treatment after film
formation. Such a step will improve the quality of the organic thin film
and increase the electron mobility or hole mobility, by promoting
interaction between the nitrogen-containing compounds. The treatment
temperature for annealing is preferably a temperature between 50°
C. and near the glass transition temperature (Tg) of the
nitrogen-containing compound, and more preferably a temperature between
(Tg-30° C.) and Tg. The annealing treatment time is preferably
from 1 minute to 10 hours and more preferably from 10 minutes to 1 hour.
The atmosphere for annealing treatment is preferably a vacuum or an inert
gas atmosphere.

[0198]Since the organic thin film of the present invention has an electron
transport or hole transport property, by controlling the transport of
electrons or holes introduced from the electrode or charge generated by
photoabsorption, the organic thin film can be used in various organic
thin-film devices such as organic thin-film transistors, organic solar
cells, optical sensors and the like. When an organic thin film of the
present invention is used in such organic thin-film devices, it is
preferably used after orientation by orienting treatment in order to
further enhance the electron transport or hole transport properties.

[0199][Organic Thin-Film Device]

[0200]Because the organic thin film of the embodiment described above
comprises a nitrogen-containing compound according to the embodiment
described above, it has excellent charge (electron or hole) transport
properties. The organic thin film can therefore efficiently transport
electrons or holes introduced from an electrode or the like, or
electrical charge generated by photoabsorption, thus allowing application
of the organic thin film in various electrical devices (organic thin-film
devices). The nitrogen-containing compounds of the embodiment described
above are also environmentally stable and have excellent solubility in
organic solvents, and can therefore be used to form thin films to allow
production of organic thin-film devices with stable performance even in
ordinary air. Examples of organic thin-film devices will now be
described.

[0201](Organic Thin-Film Transistor)

[0202]An organic thin-film transistor according to a preferred embodiment
will be explained first. The organic thin-film transistor may have a
structure comprising a source electrode and drain electrode, an organic
thin-film layer (active layer) containing a nitrogen-containing compound
of the present invention which is to act as a current channel between
them, and a gate electrode that is to control the level of current
flowing through the current channel, and the examples of the transistor
include a field-effect type or static induction type.

[0203]A field-effect type organic thin-film transistor may have a
structure comprising a source electrode and drain electrode, an organic
thin-film layer (active layer) containing a nitrogen-containing compound
of the present invention which is to act as a current channel between
them, a gate electrode that is to control the level of current flowing
through the current channel, and an insulating layer situated between the
active layer and the gate electrode. Most preferably, the source
electrode and drain electrode are provided in contact with the organic
thin-film layer (active layer) containing the nitrogen-containing
compound of the present invention, and the gate electrode is provided
sandwiching the insulating layer which is also in contact with the
organic thin-film layer.

[0204]A static induction-type organic thin-film transistor has a structure
comprising a source electrode and drain electrode, an organic thin-film
layer containing a nitrogen-containing compound of the present invention
which is to act as a current channel between them and a gate electrode
that is to control the level of current flowing through the current
channel, preferably with the gate electrode in the organic thin-film
layer. Most preferably, the source electrode, drain electrode and gate
electrode provided in the organic thin-film layer are in contact with the
organic thin-film layer comprising the nitrogen-containing compound of
the present invention. The structure of the gate electrode may be any one
that forms a current channel for flow from the source electrode to the
drain electrode, and that allows the level of current flowing through the
current channel to be controlled by the voltage applied to the gate
electrode; an example of such a structure is a comb shaped electrode.

[0205]FIG. 1 is a schematic cross-sectional view of an organic thin-film
transistor (field-effect type organic thin-film transistor) according to
a first embodiment. The organic thin-film transistor 100 shown in FIG. 1
comprises a substrate 1, a source electrode 5 and drain electrode 6
formed at a prescribed spacing on the substrate 1, an active layer 2
formed on the substrate 1 covering the source electrode 5 and drain
electrode 6, an insulating layer 3 formed on the active layer 2, and a
gate electrode 4 formed on the insulating layer 3 covering the region of
the insulating layer 3 between the source electrode 5 and drain electrode
6.

[0206]FIG. 2 is a schematic cross-sectional view of an organic thin-film
transistor (field-effect type organic thin-film transistor) according to
a second embodiment. The organic thin-film transistor 110 shown in FIG. 2
comprises a substrate 1, a source electrode 5 formed on the substrate 1,
an active layer 2 formed on the substrate 1 covering the source electrode
5, a drain electrode 6 formed on the active layer 2 at a prescribed
spacing from the source electrode 5, an insulating layer 3 formed on the
active layer 2 and drain electrode 6, and a gate electrode 4 formed on
the insulating layer 3 covering the region of the insulating layer 3
between the source electrode 5 and drain electrode 6.

[0207]FIG. 3 is a schematic cross-sectional view of an organic thin-film
transistor (field-effect type organic thin-film transistor) according to
a third embodiment. The organic thin-film transistor 120 shown in FIG. 3
comprises a substrate 1, an active layer 2 formed on the substrate 1, a
source electrode 5 and drain electrode 6 formed at a prescribed spacing
on the active layer 2, an insulating layer 3 foamed on the active layer 2
covering the source electrode 5 and drain electrode 6, and a gate
electrode 4 formed on the insulating layer 3, covering a portion of the
region of the insulating layer 3 under which the source electrode 5 is
formed and a portion of the region of the insulating layer 3 under which
the drain electrode 6 is formed.

[0208]FIG. 4 is a schematic cross-sectional view of an organic thin-film
transistor (field-effect type organic thin-film transistor) according to
a fourth embodiment. The organic thin-film transistor 130 shown in FIG. 4
comprises a substrate 1, a gate electrode 4 fowled on the substrate 1, an
insulating layer 3 formed on the substrate 1 covering the gate electrode
4, a source electrode 5 and drain electrode 6 formed at a prescribed
spacing on the insulating layer 3 covering portions of the region of the
insulating layer 3 under which the gate electrode 4 is formed, and an
active layer 2 formed on the insulating layer 3 covering portions of the
source electrode 5 and drain electrode 6.

[0209]FIG. 5 is a schematic cross-sectional view of an organic thin-film
transistor (field-effect type organic thin-film transistor) according to
a fifth embodiment. The organic thin-film transistor 140 shown in FIG. 5
comprises a substrate 1, a gate electrode 4 formed on the substrate 1, an
insulating layer 3 formed on the substrate 1 covering the gate electrode
4, a source electrode 5 formed on the insulating layer 3 covering a
portion of the region of the insulating layer 3 under which the gate
electrode 4 is formed, an active layer 2 formed on the insulating layer 3
covering a portion of the source electrode 5, and a drain electrode 6
formed on the insulating layer 3 at a prescribed spacing from the source
electrode 5 and covering a portion of the region of the active layer 2
under which the gate electrode 4 is formed.

[0210]FIG. 6 is a schematic cross-sectional view of an organic thin-film
transistor (field-effect type organic thin-film transistor) according to
a sixth embodiment. The organic thin-film transistor 150 shown in FIG. 6
comprises a substrate 1, a gate electrode 4 formed on the substrate 1, an
insulating layer 3 formed on the substrate 1 covering the gate electrode
4, an active layer 2 formed covering the region of the insulating layer 3
under which the gate electrode 4 is formed, a source electrode 5 formed
on the insulating layer 3 covering a portion of the region of the active
layer 2 under which the gate electrode 4 is formed, and a drain electrode
6 formed on the insulating layer 3 at a prescribed spacing from the
source electrode 5 and covering a portion of the region of the active
layer 2 under which the gate electrode 4 is formed.

[0211]FIG. 7 is a schematic cross-sectional view of an organic thin-film
transistor (static induction type organic thin-film transistor) according
to a seventh embodiment. The organic thin-film transistor 160 shown in
FIG. 7 comprises a substrate 1, a source electrode 5 formed on the
substrate 1, an active layer 2 formed on the source electrode 5, a
plurality of gate electrodes 4 formed at prescribed spacings on the
active layer 2, an active layer 2a formed on the active layer 2 covering
all of the gate electrodes 4, wherein the material composing the active
layer 2a may be the same as or different from that of the active layer 2,
and a drain electrode 6 formed on the active layer 2a.

[0212]In the organic thin-film transistors of the first to seventh
embodiments, the active layer 2 and/or the active layer 2a contains a
nitrogen-containing compound of the present invention and forms a current
channel between the source electrode 5 and drain electrode 6. The gate
electrode 4 controls the level of current flowing through the current
channel of the active layer 2 and/or active layer 2a by application of
voltage.

[0213]This type of field-effect type organic thin-film transistor can be
manufactured by a publicly known process, such as the process described
in Japanese Unexamined Patent Publication HEI No. 5-110069, for example.
The static induction type organic thin-film transistor can also be
manufactured by a publicly known process such as the process described in
Japanese Unexamined Patent Publication No. 2004-006476, for example.

[0214]The substrate 1 is not particularly restricted so long as it does
not impair the characteristics of the organic thin-film transistor, and a
glass panel, flexible film substrate or plastic panel may be used.

[0215]Since organic solvent-soluble compounds are highly advantageous and
preferred in forming the active layer 2, by using the organic thin-film
production method of the present invention described above, organic thin
films composed of the active layer 2 can be formed.

[0216]The insulating layer 3 in contact with the active layer 2 is not
particularly restricted so long as it is a material with high electrical
insulating properties, and any publicly known one may be used. Examples
include SiOx, SiNx, Ta2O5, polyimide, polyvinyl alcohol,
polyvinylphenol, organic glass and photoresists. From the viewpoint of
low voltage, a material with high permittivity is preferred.

[0217]When the active layer 2 is formed on the insulating layer 3, it may
be formed after surface modification by treatment of the surface of the
insulating layer 3 with a surface treatment agent such as a silane
coupling agent in order to improve the interfacial properties between the
insulating layer 3 and active layer 2. As examples of surface treatment
agents there may be mentioned long-chain alkylchlorosilanes, long-chain
alkylalkoxysilanes, fluorinated alkylchlorosilanes, fluorinated
alkylalkoxysilanes and silylamine compounds such as hexamethyldisilazane.
Before treatment with the surface treatment agent, the insulating layer
surface may be pre-treated by ozone UV or O2 plasma.

[0218]After the organic thin-film transistor has been fabricated, in order
to protect the device, it is preferable that a protecting film is formed
on the organic thin-film transistor. This will help prevent reduction in
the characteristics of the organic thin-film transistor due to shielding
from air. A protecting film can also minimize adverse effects from the
step of forming an operating display device on the organic thin-film
transistor.

[0219]Examples of the method of forming the protecting film include
covering with a UV curing resin, thermosetting resin, inorganic SiONx
film or the like. For effective shielding from air, the steps after
fabrication of the organic thin-film transistor and before formation of
the protecting film are preferably carried out without exposure to air
(for example, in a dry nitrogen atmosphere or in a vacuum).

[0220]Application of an organic thin film of the present invention in a
solar cell will now be explained. FIG. 8 is a schematic cross-sectional
view of a solar cell according to an embodiment. The solar cell 200 shown
in FIG. 8 comprises a substrate 1, a first electrode 7a formed on the
substrate 1, an active layer 2 comprising an organic thin film that
contains a nitrogen-containing compound of the present invention formed
on the first electrode 7a, and a second electrode 7b formed on the active
layer 2.

[0221]In the solar cell of this embodiment, a transparent or
semi-transparent electrode is used for either the first electrode 7a or
the second electrode 7b. As electrode materials there may be used metals
such as aluminum, gold, silver, copper, alkali metal and alkaline earth
metals or their semi-transparent films, or transparent conductive films.
In order to obtain high open voltage, it is preferred to select the
electrodes so as to produce a large work function difference. Charge
generators, sensitizing agents and the like may also be added in order to
increase photosensitivity in the active layer 2 (organic thin film). The
substrate 1 may be a silicon substrate, glass panel, plastic panel or the
like.

[0222]Application of an organic thin film of the present invention in an
optical sensor will now be explained. FIG. 9 is a schematic
cross-sectional view of an optical sensor according to a first
embodiment. The optical sensor 300 shown in FIG. 9 comprises a substrate
1, a first electrode 7a formed on the substrate 1, an active layer 2
comprising an organic thin film that contains a nitrogen-containing
compound of the present invention formed on the first electrode 7a, a
charge generation layer 8 formed on the active layer 2 and a second
electrode 7b formed on the charge generation layer 8.

[0223]FIG. 10 is a schematic cross-sectional view of an optical sensor
according to a second embodiment. The optical sensor 310 shown in FIG. 10
comprises a substrate 1, a first electrode 7a formed on the substrate 1,
a charge generation layer 8 formed on the first electrode 7a, an active
layer 2 comprising an organic thin film that contains a
nitrogen-containing compound of the present invention formed on the
charge generation layer 8 and a second electrode 7b formed on the active
layer 2.

[0224]FIG. 11 is a schematic cross-sectional view of an optical sensor
according to a third embodiment. The optical sensor 320 shown in FIG. 11
comprises a substrate 1, a first electrode 7a formed on the substrate 1,
an active layer 2 comprising an organic thin film that contains a
nitrogen-containing compound of the present invention formed on the first
electrode 7a, and a second electrode 7b fowled on the active layer 2.

[0225]In the optical sensors of the first to third embodiments, a
transparent or semi-transparent electrode is used for either the first
electrode 7a or the second electrode 7b. The charge generation layer 8 is
a layer that generates an electrical charge upon absorption of light. As
electrode materials there may be used metals such as aluminum, gold,
silver, copper, alkali metal and alkaline earth metals or their
semi-transparent films, or transparent conductive films. Carrier
generators, sensitizing agents and the like may also be added in order to
increase photosensitivity in the active layer 2 (organic thin film). The
substrate 1 may be a silicon substrate, glass panel, plastic panel or the
like.

[0226]The present invention was explained above in detail based on
embodiments thereof. However, the present invention is not limited to
these described embodiments. The present invention may also be applied in
a variety of modifications so long as the gist thereof is maintained.

EXAMPLES

[0227]The present invention will now be explained in detail by examples,
with the understanding that the present invention is not limited to the
examples.

[0228]An example of the first invention group will be explained first.

[0229](Measuring Conditions)

[0230]The nuclear magnetic resonance (NMR) spectra were measured using a
JMN-270 (270 MHz for 1H measurement) or a JMNLA-600 (600 MHz for
19F measurement), both trade names of JEOL Corp. The chemical shifts
are represented as parts per million (ppm). Tetramethylsilane (TMS) was
used as the internal standard (0 ppm). The coupling constant (J) is
represented in Hz, and the symbols s, d, t, q, m and br respectively
represent singlet, doublet, triplet, quartet, multiplet and broad. The
mass spectrometry (MS) was performed using a GCMS-QP5050A, trade name of
Shimadzu Corp., by electron ionization (EI) or direct inlet (DI). The
silica gel used for separation by column chromatography was Silicagel 60N
(40-50 μm), trade name of Kanto Kagaku Co., Ltd. All of the chemical
substances were reagent grade and purchased from Wako Pure Chemical
Industries, Ltd., Tokyo Kasei Kogyo Co., Ltd., Kanto Kagaku Co., Ltd.,
Nacalai Tesque, Inc., Sigma Aldrich Japan, KK. or Daikin Chemicals Co.,
Ltd.

[0231]Cyclic voltammetry was performed using a CV-50W, trade name of BAS
as the measuring apparatus, with a Pt electrode by BAS as the work
electrode, Pt wire as the counter electrode and Ag wire as the reference
electrode. The sweep rate during the measurement was 100 mV/sec, and the
scanning potential range was -2.0 V to 1.6 V. The reduction potential and
oxidation potential were measured after completely dissolving
1×10-3 mol/L of the conjugated compound and 0.1 mol/L of
tetrabutylammonium hexafluorophosphate (TBAPF6) as a supporting
electrolyte in a monofluorobenzene solvent.

Example 1

Synthesis of Compound A>

[0232]To a heat-dried stoppered test tube there were added
5,5'-ditributylstannyl-2,2'-bithiophene (1.49 g, 2.00 mmol),
4'-bromo-2,2,2-trifluoroacetophenone (1.27 g, 5.00 mmol),
tetrakis(triphenylphosphine)palladium(0) (100 mg, 0.087 mmol) and toluene
(20 mL), and reaction was conducted at 120° C. with nitrogen
exchange. After 19 hours, water was added, extraction was performed with
chloroform, and the organic phase dried over magnesium sulfate and
concentrated under reduced pressure. The obtained concentrate was rinsed
with methanol and ether and subjected to sublimation purification in a
vacuum, to obtain compound A represented by the following formula (21)
(863 mg, 85% yield) as a red solid. The reduction potential of compound A
was -1.70 V.

[0234]To a heat-dried stoppered test tube there were added
5,5'-dibromo-2,2'-bithiophene (242 mg, 0.75 mmol), 4-acetylphenylboronic
acid (366 mg, 2.23 mmol), tetrakis(triphenylphosphine)palladium(0) (40
mg, 0.035 mmol), sodium hydrogencarbonate (438 mg, 5.21 mmol) and a
dimethoxyethane (DME)/water mixed solvent (7 mL), and reaction was
conducted at 100° C. with nitrogen exchange. After 14 hours, the
reaction mixture was concentrated under reduced pressure to obtain a
concentrate. The obtained concentrate was rinsed with methanol and ether
and then subjected to sublimation purification in a vacuum, to obtain
compound B represented by the following formula (22) (205 mg, 83% yield)
as a light yellow solid. The reduction potential of compound B could not
be measured because it was insoluble in monofluorobenzene.

[0236]The intermediate as the starting material for the target compound
was synthesized using compound (23a) as the starting material, according
to the following Scheme 1. This will now be explained in detail.

##STR00035##

Synthesis of Compound D

[0237]Compound C-1 represented by the above formula (23a) was synthesized
by a method described in the literature (J. Chem. Soc. Perkin Trans 1.
Organic and Bio-Organic Chemistry 1992, 21, 2985-2988). Next, compound
C-1 (1.00 g, 6.58 mol) and the fluorinating agent Selectfluor®
(registered trademark) (5.60 g, 15.8 mol) were placed in a 300 mL
three-necked flask and THF (65 mL) was added to dissolve them.
Tetrabutylammonium hydroxide (TBAH) (10% methanol solution) (3.76 g, 14.5
mol) was then added and the mixture was stirred at 0° C. for 12
hours. The solvent was distilled off under reduced pressure, and then
water was added, the aqueous phase was extracted with ethyl acetate, and
the organic phase was dried over magnesium sulfate and concentrated under
reduced pressure. The obtained concentrate was purified by silica gel
column chromatography (hexane/ethyl acetate=3/1) to obtain compound C-2
represented by the above formula (23b) (0.934 g, 75%) as a light yellow
solid.

[0239]Compound C-2 (1.97 g, 10.48 mmol) was placed in a 200 mL
three-necked flask, N,N'-dimethylformamide (DMF) (50 mL) was added to
dissolve it, and then 2-chloromethanol (3.37 g, 41.91 mmol) was further
added. Potassium tert-butoxide dissolved in DMF (50 mL) was then added
dropwise thereto at -60° C. Upon completion of the dropwise
addition, the mixture was stirred at room temperature for 4 hours, and
water was added to suspend the reaction. The aqueous phase was extracted
with ethyl acetate and rinsed with water, and then the organic phase was
dried over magnesium sulfate, filtered and concentrated under reduced
pressure. The obtained concentrate was purified by silica gel column
chromatography (hexane/ethyl acetate=3/1) to obtain compound D
represented by the above formula (24) (1.58 g, 55% yield) as a white
solid.

[0241]Compound D (500 mg, 1.81 mmol) was placed in a 50 mL three-necked
flask, and THF (18 mL) was added to dissolve it. Next, n-butyllithium
(1.58 M, 2.29 mL, 3.62 mmol) was added thereto at -78° C. After
stirring for 0.5 hour, tributyltin chloride (1.09 mL, 3.98 mmol) was
added and the temperature was slowly raised to room temperature. After 1
hour, water was added to suspend the reaction. The aqueous phase was
extracted with ethyl acetate and rinsed with water, and then the organic
phase was dried over magnesium sulfate, filtered and concentrated under
reduced pressure. The obtained concentrate was purified by alumina-column
chromatography (hexane/ethyl acetate=10:1) to obtain compound E
represented by the above formula (25) (1.02 g, 99% yield) as a colorless
liquid.

[0243]Compound D (1.00 g, 3.62 mmol) was placed in a 100 mL three-necked
flask, and THF (30 mL) was added to dissolve it. Next, n-butyllithium
(1.58 M, 2.75 mL, 4.34 mmol) was added thereto at -78° C. After
stirring for 0.5 hour, bromine (0.29 mL, 5.43 mmol) was added and the
temperature was slowly raised to room temperature. After 1 hour, water
was added to suspend the reaction. The aqueous phase was extracted with
ethyl acetate and rinsed with saturated aqueous sodium thiosulfate, and
after further rinsing with water, the organic phase was dried over
magnesium sulfate. The solvent was distilled off under reduced pressure,
and the crude product was passed through silica gel column chromatography
(hexane/ethyl acetate=3:1) to obtain a crude product of the intermediate
compound represented by the above formula (26a). This was placed in a 100
mL volumetric flask and dissolved in THF (30 mL). Concentrated sulfuric
acid (30 mL) was added and the mixture was stirred at room temperature
for 12 hours. The reaction mixture was poured into ice and extracted with
water. The organic phase was rinsed with aqueous saturated sodium
hydrogencarbonate and water in that order and dried over magnesium
sulfate, and then filtered and concentrated under reduced pressure. The
obtained concentrate was purified by silica gel column chromatography
(ethyl acetate) to obtain compound F represented by the above formula
(26b) (877 mg, 91% in 2 steps) as a brown solid.

[0245]After placing 2,5-dibromothiophene (18 mg, 0.0738 mmol), compound E
(100 mg, 0.177 mmol) and tetrakis(triphenylphosphine)palladium(0) (17 mg,
0.0148 mmol) in a test tube, toluene (1 mL) was added to dissolve them.
After stirring the mixture at 120° C. for 12 hours, it was allowed
to cool at room temperature. The solvent was then distilled off under
reduced pressure, and the crude product was passed through alumina-column
chromatography (hexane/ethyl acetate=3:1) and purified by GPC
(chloroform) to obtain compound G represented by the following formula
(27) (35 mg, 74%) as a light yellow solid.

[0247]Compound G (35 mg, 0.0550 mmol) was placed in a test tube, and THF
(3 mL) was added to dissolve it. Concentrated sulfuric acid (3 mL) was
added and the mixture was stirred at room temperature for 12 hours. The
reaction mixture was poured into ice and extracted with water. The
organic phase was rinsed with aqueous saturated sodium hydrogencarbonate
and water in that order and dried over magnesium sulfate, and then
filtered and concentrated under reduced pressure. The obtained
concentrate was rinsed with diethyl ether to obtain compound H
represented by the following formula (28) (18 mg, 72% yield) as a red
solid. The reduction potential of compound H was -1.24 V.

[0249]After placing
1,3-dibromo-5,5-difluoro-4H-cyclopenta[c]thiophene-4,6(5H)-dione (26 mg,
0.0738 mmol), compound E (100 mg, 0.177 mmol) and
tetrakis(triphenylphosphine)palladium(0) (17 mg, 0.0148 mmol) in a test
tube, toluene (1 mL) was added to dissolve them. After stirring the
mixture at 120° C. for 12 hours, it was allowed to cool at room
temperature. The solvent was then distilled off under reduced pressure,
and the crude product was passed through alumina-column chromatography
(chloroform) and purified by GPC (chloroform) to obtain compound I
represented by the following formula (29) (33 mg, 61%) as a yellow solid.

[0251]Compound I (72 mg, 0.0978 mmol) was placed in a test tube, and THF
(7 mL) was added to dissolve it. Concentrated sulfuric acid (7 mL) was
added and the mixture was stirred at room temperature for 12 hours. The
reaction mixture was poured into ice and extracted with water, and then
the organic phase was rinsed with aqueous saturated sodium
hydrogencarbonate and water in that order and dried over magnesium
sulfate, and then filtered and concentrated under reduced pressure. The
obtained concentrate was recrystallized with hexane/chloroform to obtain
compound J represented by the following formula (30) (21 mg, 38%) as a
light a yellow solid. The reduction potential of compound J was -0.66 V.

[0253]In a heat-dried stoppered test tube there were placed
1,3-dibromo-5,5-difluoro-4H-cyclopenta[c]thiophene-4,6(5H)-dione (589 mg,
1.70 mmol), 2-tributylstannylthiophene (1.32 g, 5.10 mmol) and
tetrakis(triphenylphosphine)palladium(0) (196 mg, 0.17 mmol). Toluene (10
mL) was added and reaction was conducted at 120° C. The mixture
was allowed to cool after 12 hours and then extracted with ethyl acetate,
and the organic phase was dried over anhydrous sodium sulfate and then
filtered and concentrated under reduced pressure. The obtained
concentrate was purified by column chromatography (silica gel, chloroform
charge) using hexane/ethyl acetate (4/1) as the developing solvent, to
obtain compound K represented by the following formula (31) (186 mg, 31%)
as a red solid. The reduction potential of compound K was -1.34 V.

[0255]After placing 5,5'-bis(tributylstannyl)-2,2'-bithiophene (413 mg,
0.555 mmol), compound F (326 mg, 1.22 mmol) and
tetrakis(triphenylphosphine)palladium(0) (64 mg, 0.056 mmol) in a test
tube, toluene (6 mL) was added to dissolve them. After stirring the
mixture at 120° C. for 12 hours, it was allowed to cool at room
temperature. The reaction mixture was filtered with Celite and the
solvent was distilled off under reduced pressure, after which the
obtained solid was rinsed with hexane to obtain compound L represented by
the following formula (32) (35 mg, 74%) as a dark violet solid.

[0257]A substrate was prepared by forming a silicon oxide film as the
insulating layer, by thermal oxidation to a thickness of 300 nm on the
surface of a highly doped p-type silicon substrate as the gate electrode.
The lift-off method was used to form on this substrate a comb-shaped
source electrode and drain electrode with a channel width of 38 mm and a
channel length of 5 μm. The electrode-formed substrate was subjected
to ultrasonic cleaning for 10 minutes in acetone and for 10 minutes in
isopropyl alcohol, after which it was irradiated with ozone UV for 30
minutes to clean the surface. An organic thin film of compound A
synthesized in Example 1 was formed on the cleaned substrate by vacuum
vapor deposition, to fabricate organic thin-film device 1. The organic
transistor property was measured by varying the gate voltage Vg from 0 to
100 V and the source-drain voltage Vsd from 0 to 100 V for the organic
thin-film device 1 in a vacuum, and a satisfactory n-type semiconductor
Id-Vg characteristic was obtained. The mobility during this time was
3.4×10-3 cm2/Vs, and the on/off ratio was satisfactory at
104-105.

[0258]An organic thin film of compound B synthesized in Comparative
Example 1 was fanned in the same manner as Example 5 to fabricate organic
thin-film device 2. The organic transistor property was measured by
varying the gate voltage Vg from 0 to 100 V and the source-drain voltage
Vsd from 0 to 100 V for the obtained organic thin-film device 2 in a
vacuum, to obtain the Id-Vg characteristic of the p-type semiconductor.
The mobility during this time was 1.8×10-5 cm2/Vs, and
the on/off ratio was low at 102.

[0259]An organic thin film of compound L synthesized in Example 4 was
formed in the same manner as Example 5, to fabricate organic thin-film
device 3. The organic transistor property was measured by varying the
gate voltage Vg from 0 to 100 V and the source-drain voltage Vsd from 0
to 100 V for the obtained organic thin-film device 3 in a vacuum, to
obtain a satisfactory Id-Vg characteristic for the n-type semiconductor.
The mobility during this time was 1.5×10-3 cm2/Vs, and
the on/off ratio was satisfactory at 104.

[0260]A substrate was prepared by forming a silicon oxide film, as the
insulating layer, by thermal oxidation to a thickness of 300 nm on the
surface of a highly doped p-type silicon substrate as the gate electrode.
The substrate was immersed in hexamethyldisilazane (HMDS) by Aldrich at
50° C. for 7 hours for surface treatment. An organic thin film of
compound A was then accumulated on the surface-treated substrate to a
film thickness of 30 nm, by vacuum vapor deposition at room temperature.
Au was formed to a thickness of 30 nm on the organic thin film by vapor
deposition through a shadow mask, to form a source electrode and drain
electrode with a channel width of 5.5 mm and a channel length of 50
μm, thus fabricating organic thin-film device 4. The transistor
property of the obtained organic thin-film device 4 was measured while
varying the gate voltage Vg and the source-drain voltage Vsd in nitrogen,
and as a result a satisfactory Id-Vg property was confirmed and a drain
current of Id=1.1×10-4 A flowed at Vg=100 V, Vd=100 V. The
mobility was 0.12 cm2/Vs, and the threshold voltage with current on
was Vth=60 V. These results confirmed that the organic thin-film device 4
using compound A effectively functions as an n-type organic transistor.

[0261]An organic thin-film device 5 was fabricated in the same manner as
Example 7 using an organic thin film of compound L instead of an organic
thin film of compound A. The transistor property of the obtained organic
thin-film device 5 was measured while varying the gate voltage Vg and the
source-drain voltage Vsd in nitrogen, and as a result a satisfactory
Id-Vg property was confirmed and a drain current of
Id=1.5×10-5 A flowed at Vg=80 V, Vd=100 V. The mobility was
0.013 cm2/Vs, the on/off ratio was 105, and the threshold
voltage with current on was Vth=38 V. These results confirmed that the
organic thin-film device 5 using compound L effectively functions as an
n-type organic transistor.

Example 9

Synthesis of Compound M>

[0262]After placing 2-bromo-3-hexylthiophene (600 mg, 2.43 mmol), compound
E synthesized in Example 2 (1.51 g, 2.67 mmol) and
tetrakis(triphenylphosphine)palladium(0) (281 mg, 0.243 mmol) in a
heat-dried stoppered test tube, toluene (25 mL) was added to dissolve
them. After stirring the mixture at 120° C. for 12 hours, it was
allowed to cool at room temperature. The solvent was then distilled off
under reduced pressure, and the obtained crude product was purified by
silica gel column chromatography (hexane/ethyl acetate=10:1) to obtain
compound M represented by the following formula (33) (960 mg, 81% yield)
as a yellow liquid.

[0264]Compound M (300 mg, 0.679 mmol) was placed in a heat-dried 20 mL
three-necked flask, and THF (7 mL) was added to dissolve it. Next,
n-butyllithium (1.58 M, 0.88 mL, 1.39 mmol) was added thereto at
-78° C. After stirring for 1 hour, tributyltin chloride (0.221 ml,
0.814 mmol) was added and the temperature was slowly raised to room
temperature. After 0.5 hour, water was added to suspend the reaction. The
aqueous phase was extracted with ethyl acetate and rinsed with water, and
then the organic phase was dried over magnesium sulfate. The solvent was
distilled off under reduced pressure, and the obtained crude product was
purified by alumina column chromatography (hexane/ethyl acetate=10:1) to
obtain compound N represented by the following formula (34) (440 mg, 89%
yield) as a yellow liquid.

[0266]After placing
1,3-dibromo-5,5-difluoro-4H-cyclopenta[c]thiophene-4,6(5H)-dione (93 mg,
0.27 mmol), compound N (435 mg, 0.594 mmol) and
tetrakis(triphenylphosphine)palladium(0) (31 mg, 0.027 mmol) in a test
tube, toluene (3 mL) was added to dissolve them. After stirring the
mixture at 120° C. for 12 hours, it was allowed to cool at room
temperature. The solvent was distilled off under reduced pressure, and
the obtained crude product was passed through silica gel column
chromatography (CHCl3) and then purified by GPC(CHCl3) to
obtain compound O represented by the following formula (35) (230 mg, 80%
yield) as a red solid.

[0268]Compound O (250 mg, 0.234 mmol) was placed in a volumetric flask (30
mL) and THF (3 mL) was added to dissolve it. Concentrated sulfuric acid
(10 mL) was added and the mixture was stirred at room temperature for 12
hours. The obtained reaction mixture was poured into ice and extraction
was performed with ethyl acetate. The organic phase was rinsed with
aqueous saturated sodium hydrogencarbonate and then with water and dried
over magnesium sulfate. The solvent was distilled off under reduced
pressure, and the obtained solid was purified by GPC(CHCl3) to
obtain compound P represented by the following formula (36) (99 mg, 47%
yield) as a red solid.

[0270]After placing 5,5'-dibromo-4,4'-dihexyl-2,2'-bithiophene (492 mg,
1.00 mmol) in a 20 mL three-necked flask, THF (10 mL) was added to
dissolve it. Next, n-butyllithium (1.58 M, 1.39 mL, 2.20 mmol) was added
thereto at -78° C. After stirring for 1 hour, tributyltin chloride
(0.543 ml, 2.00 mmol) was added and the temperature was slowly raised to
room temperature. After 2 hours, water and a trace amount of hydrochloric
acid were added to suspend the reaction. The aqueous phase was extracted
with diethyl ether and rinsed with water, and then the organic phase was
dried over magnesium sulfate. The solvent was distilled off under reduced
pressure, and the obtained liquid was purified by GPC(CHCl3) to
obtain compound Q represented by the following formula (37) (630 mg, 69%
yield) as a yellow liquid.

[0272]After placing compound Q (50 mg, 0.055 mmol), compound F synthesized
in Example 2 (32 mg, 0.12 mmol) and
tetrakis(triphenylphosphine)palladium(0) (6 mg, 0.005 mmol) in a
stoppered test tube, toluene (1 mL) was added to dissolve them. After
stirring the mixture at 120° C. for 12 hours, it was allowed to
cool at room temperature. The solvent was distilled off under reduced
pressure, and the crude product was passed through silica gel column
chromatography (CHCl3) and then purified by GPC(CHCl3) to
obtain compound R represented by the following formula (38) (19 mg, 49%
yield) as an orange solid. The oxidation potential of compound R was 0.48
V, and the reduction potential was -1.87 V. The peak wavelength in the
absorption spectrum was 472 nm.

[0274]After placing
2,7-bis(1,3,2-dioxaborolan-2-yl)-9,9-di(n-octyl)fluorene, compound F,
tetrakis(triphenylphosphine)palladium(0), potassium carbonate and a
tetrahydrofuran (THF)/water mixed solvent in a heat-dried stoppered test
tube, it is exchanged with nitrogen and reaction is conducted at
100° C. After 12 hours, the solvent is distilled off under reduced
pressure, and the obtained crude product may be passed through silica gel
column chromatography and then purified by GPC (CHCl3) to obtain the
target compound S represented by the following formula (39).

##STR00048##

Example 12

Synthesis of Compound T

[0275]After placing 2,7-dibromo-9,9-di(n-octyl)fluorene, compound N and
tetrakis(triphenylphosphine)palladium(0) in a stoppered test tube,
toluene is added to dissolve them. After stirring the mixture at
120° C. for 12 hours, it is allowed to cool at room temperature.
The solvent is distilled off under reduced pressure, and the obtained
crude product is passed through silica gel column chromatography and then
purified by GPC(CHCl3). The obtained compound is placed in a
volumetric flask and dissolved in THF, and then concentrated sulfuric
acid is added and the mixture is stirred at room temperature for 12
hours. The reaction mixture is then poured into ice and extracted with
ethyl acetate, and the organic layer is subsequently rinsed with aqueous
saturated sodium hydrogencarbonate and water and dried over magnesium
sulfate. The solvent may then be distilled off under reduced pressure and
the obtained solid purified by GPC(CHCl3) to obtain compound T
represented by the following formula (40).

##STR00049##

Example 13

Synthesis of Compound Ua

[0276]After placing 2,5-dibromothiophene (48 mg, 0.199 mmol),
5-tributyl-3-hexylthiophene (200 mg, 0.437 mmol) and
tetrakis(triphenylphosphine)palladium(0) (11 mg, 0.0199 mmol) in a
heat-dried stoppered test tube, toluene (2 mL) was added to dissolve
them. After stirring the mixture at 120° C. for 12 hours, it was
allowed to cool at room temperature. The solvent was then distilled off
under reduced pressure, and the obtained crude product was purified by
silica gel column chromatography (hexane) to obtain compound Ua
represented by the following formula (41a) (48 mg, 58% yield) as a yellow
liquid.

[0282]After placing
1,3-dibromo-5,5-difluoro-4H-cyclopenta[c]thiophene-4,6(5H)-dione (400 mg,
1.16 mmol), 2-bromo-3-hexylthiophene (1.33 g, 2.90 mmol) and
tetrakis(triphenylphosphine)palladium(0) (134 mg, 0.116 mmol) in a test
tube, toluene (12 mL) was added to dissolve them. After stirring the
mixture at 120° C. for 12 hours, it was allowed to cool at room
temperature. The solvent was distilled off under reduced pressure, and
the obtained crude product was passed through silica gel column
chromatography (CHCl3) and then purified by GPC(CHCl3) to
obtain compound V represented by the following formula (42) (247 mg, 41%
yield) as a red solid.

[0284]Compound V (103 mg, 0.198 mmol) was placed in a heat-dried 20 mL
volumetric flask while cooling on ice, and DMF (2 mL) was added to
dissolve it. Next, N-bromosuccinimide (NBS) (74 mg, 0.416 mmol) was added
and the mixture was slowly heated to 80° C. After stirring for 12
hours, water was added to suspend the reaction. The aqueous phase was
extracted with ethyl acetate and rinsed with water, and then the organic
phase was dried over magnesium sulfate. The solvent was distilled off
under reduced pressure, and then the obtained crude product was purified
by silica gel column chromatography (ethyl acetate) to obtain compound W
represented by the following formula (43) (125 mg, 91% yield) as a red
solid.

[0286]After placing compound W (125 mg, 0.184 mmol), compound E (240 mg,
0.424 mmol) and tetrakis(triphenylphosphine)palladium(0) (21 mg, 0.018
mmol) in a test tube, toluene (2 mL) was added to dissolve them. After
stirring the mixture at 120° C. for 12 hours, it was allowed to
cool at room temperature. The solvent was then distilled off under
reduced pressure, and the obtained crude product was passed through
alumina column chromatography (CHCl3) and then purified by
GPC(CHCl3). It was then placed in a volumetric flask (50 mL) and
dissolved in THF (1 mL). Concentrated sulfuric acid (20 mL) was added and
the mixture was stirred at room temperature for 12 hours. The reaction
mixture was poured into ice and extraction was performed with ethyl
acetate. The organic phase was rinsed with aqueous saturated sodium
hydrogencarbonate and then with water, and dried over magnesium sulfate.
The solvent was distilled off under reduced pressure, and the obtained
solid was purified by GPC(CHCl3) to obtain compound X represented by
the following formula (44) (23 mg, 14% yield in 2 steps) as a red solid.

[0288]Thus, the organic thin-film devices comprising organic thin films
containing π-conjugated compounds of the present invention fabricated
in Examples 5, 6, 7 and 8 had more satisfactory electron mobility than
the organic thin-film device fabricated in Comparative Example 3. This
confirmed that the π-conjugated compounds of the present invention can
be utilized as n-type organic semiconductors with excellent electron
transport properties.

[0289]Examples of the second invention group will now be described.

[0290](Measuring Conditions)

[0291]The nuclear magnetic resonance (NMR) spectra were measured using a
JMN-270 (270 MHz for 1H measurement) or a JMNLA-600 (600 MHz for
19F measurement), both trade names of JEOL Corp. The chemical shifts
are represented as parts per million (ppm). Tetramethylsilane (TMS) was
used as the internal reference (0 ppm). The coupling constant (J) is
represented in Hz, and the symbols s, d, t, q, m and br respectively
represent singlet, doublet, triplet, quartet, multiplet and broad. The
mass spectrometry (MS) was performed using a GCMS-QP5050A, trade name of
Shimadzu Corp., by electron ionization (EI) or direct inlet (DI). The
silica gel used for separation by column chromatography was Silicagel 60N
(40-50 μm), trade name of Kanto Kagaku Co., Ltd. All of the chemical
substances were reagent grade and purchased from Wako Pure Chemical
Industries, Ltd., Tokyo Kasei Kogyo Co., Ltd., Kanto Kagaku Co., Ltd.,
Nacalai Tesque, Inc., Sigma Aldrich Japan, KK. or Daikin Chemicals Co.,
Ltd.

Example α-1

Synthesis of Compound α-A

[0292]Thiazole (8.50 g, 100 mmol) and tetrahydrofuran (150 mL) were placed
in a heat-dried volumetric flask. The mixture was then exchanged with
nitrogen and cooled to -78° C., after which n-butyllithium (2.66
M, 41.0 mL, 110 mmol) was added for reaction. After 1 hour,
triisopropylsilyl chloride (23.5 mL, 110 mmol) was added at -78°
C. and the temperature was raised to room temperature. After 1 hour,
water was added and extraction was performed with ethyl acetate. The
organic phase was dried over magnesium sulfate and concentrated under
reduced pressure. It was then purified by vacuum distillation to obtain
compound α-A represented by the following formula (α-A) as
the target product (17.6 g, 73% yield) as a pale yellow liquid.

[0294]Compound α-A (9.57 g, 39.6 mmol) and tetrahydrofuran (135 mL)
were placed in a heat-dried volumetric flask. The mixture was then
exchanged with nitrogen and cooled to -78° C., after which
n-butyllithium (2.66 M, 15 mL, 39.9 mmol) was added for reaction. After 1
hour, tributyltin chloride (13.0 g, 39.9 mmol) was added at -78°
C. and the temperature was raised to room temperature. After 1 hour,
water was added and extraction was performed with ethyl acetate. The
organic phase was dried over magnesium sulfate and concentrated under
reduced pressure. It was then purified with an alumina column (hexane) to
obtain compound α-B represented by the following formula
(α-B) as the target product, (20.9 g, 99% yield) as a yellow
liquid.

[0296]Compound α-A (8.00 g, 33.1 mmol) and tetrahydrofuran (60 mL)
were placed in a heat-dried volumetric flask. The mixture was then
exchanged with nitrogen and cooled to -78° C., after which
n-butyllithium (2.66 M, 19 mL, 49.4 mmol) was added for reaction. After 1
hour, bromine (2.6 mL, 49.4 mmol) was added at -78° C. and the
temperature was raised to room temperature. After 1 hour, water was added
and extraction was performed with ethyl acetate. The organic phase was
dried over magnesium sulfate and concentrated under reduced pressure. It
was then purified with a silica gel column (hexane) to obtain compound
α-C represented by the following formula (α-C) as the target
product, (9.11 g, 86% yield) as an orange liquid.

[0298]After placing compound α-B (5.39 g, 10.2 mmol), compound
α-C (3.10 mg, 9.68 mmol), tetrakis(triphenylphosphine)palladium(0)
(500 mg, 0.433 mmol) and toluene (30 mL) in a heat-dried stoppered test
tube, it was exchanged with nitrogen and refluxed for 4 days. The mixture
was filtered with Celite and then concentrated under reduced pressure. It
was then purified with an alumina column (hexane/ethyl acetate=20:1) to
obtain compound α-D represented by the following formula
(α-D) as the target product (3.77 g, 81% yield) as a white solid.

[0300]After exchanging a heat-dried volumetric flask with nitrogen and
cooling it to -40° C., tetrahydrofuran (1 mL), diisopropylamine
(0.8 mL) and n-butyllithium (1.6 M, 3.2 mL, 5.3 mmol) were placed
therein. Next, compound α-D (385 mg, 0.801 mmol) was added and
reaction was conducted. After 1 hour, ethyl-1-piperidine carboxylate (200
mg, 1.27 mmol) was added at -40° C. and reaction was conducted.
After 1 hour, water was added and extraction was performed with ethyl
acetate. The organic phase was dried over magnesium sulfate and
concentrated under reduced pressure. It was then purified with a silica
gel column (hexane/ethyl acetate=20:1) to obtain compound α-E
represented by the following formula (α-E) as the target product
(401 mg, 99% yield) as a red solid.

[0302]Compound α-E (100 mg, 0.197 mmol) and tetrahydrofuran (2 mL)
were placed in a heat-dried volumetric flask. It was exchanged with
nitrogen and then cooled to 0° C., and then tetrabutylammonium
fluoride (1.0 M, 0.45 mL, 0.45 mmol) was added and reaction was
conducted. After 4 hours, the temperature was raised to room temperature,
water was added, and extraction was performed with ethyl acetate and
chloroform. The organic phase was rinsed with water, dried over magnesium
sulfate and concentrated under reduced pressure. It was then purified by
silica gel column chromatography (ethyl acetate) to obtain compound
α-F represented by the following formula (α-F) (30 mg, 78%
yield) as a violet compound.

[0303]TLC Rf 0.1 (ethyl acetate): GC-MS (DI):m/z=194 (M.sup.+).

##STR00061##

Example α-2

Synthesis of Compound α-G

[0304]In a heat-dried volumetric flask there were placed compound
α-E (3.00 g, 5.91 mmol), 2-ethanol chloride (1.90 g, 23.6 mmol),
DMF (160 mL) and tetrahydrofuran (80 mL). The mixture was then exchanged
with nitrogen and cooled to -78° C., after which t-butoxypotassium
(1.33 g, 11.9 mmol) was added for reaction. After 7 hours, an aqueous
solution of 10 wt % ammonium chloride was added and extraction was
performed with ethyl acetate. The organic phase was dried over magnesium
sulfate and concentrated under reduced pressure. It was then purified by
silica gel column chromatography (hexane/ethyl acetate=10:1) to obtain a
light orange solid. The obtained light orange solid and tetrahydrofuran
(50 mL) were placed in a heat-dried volumetric flask. It was exchanged
with nitrogen and then cooled to 0° C., and then
tetrabutylammonium fluoride (1.0 M, 12.5 mL, 12.5 mmol) was added and
reaction was conducted. After 1 hour, the temperature was raised to room
temperature, water was added and extraction was performed with ethyl
acetate, and then the organic phase was washed with water, dried over
magnesium sulfate and concentrated under reduced pressure. It was then
purified by silica gel column chromatography (hexane/ethyl acetate=1:1)
to obtain compound α-G represented by the following formula
(α-G) (677 mg, 48% yield) as a light brown solid.

[0306]Compound α-G (49 mg, 0.21 mmol) and tetrahydrofuran (2 mL)
were placed in a heat-dried volumetric flask. The mixture was then
exchanged with nitrogen and cooled to -78° C., after which
n-butyllithium (1.6 M, 0.30 mL, 0.48 mmol) was added for reaction. After
30 minutes, tributyltin chloride (160 mg, 0.49 mmol) was added at
-78° C. and the temperature was raised to room temperature. After
1 hour, water was added and extraction was performed with ethyl acetate.
The organic phase was dried over magnesium sulfate and concentrated under
reduced pressure. It was then purified with an alumina column (hexane) to
obtain compound α-H represented by the following formula
(α-H) as the target product, (126 mg, 75% yield) as a yellow
liquid.

[0308]After placing compound α-H (240 mg, 0.294 mmol),
4'-bromo-2,2,2-trifluoroacetophenone (223 mg, 0.881 mmol),
tetrakis(triphenylphosphine)palladium(0) (34 mg, 0.029 mmol) and toluene
(6 mL) in a heat-dried stoppered test tube, it was exchanged with
nitrogen and refluxed for 13 hours. After filtration with Celite, it was
concentrated under reduced pressure and the obtained red solid was rinsed
with methanol and diethyl ether. After placing the obtained red solid,
acetic acid (50 mL) and concentrated hydrochloric acid (3 mL) in a
volumetric flask, the mixture was heated to 100° C. After 2 hours,
the temperature was lowered to room temperature, water was added, and the
produced solid was rinsed with water, methanol and diethyl ether.
Sublimation purification was carried out under reduced pressure to obtain
compound α-I represented by the following formula (α-I) as
the target product (33 mg, 21% yield), as a green solid.

[0310]Compound α-I was subjected to X-ray structural analysis to
measure the torsional angle between adjacently bonded molecular rings, by
which highly planarity of 11-12 degrees was confirmed (FIG. 13). In
addition, the molecular crystals exhibited a π-π stack structure
with the π planes between adjacent molecules opposite each other, and
a plane spacing of 0.34 nm was confirmed (FIG. 14).

Example α-3

Synthesis of Compound α-J

[0311]After placing compound α-H,
2-bromo-5,5-difluoro-4H-cyclopenta[b]thiophene-4,6(5H)-dione,
tetrakis(triphenylphosphine)palladium(0) and toluene in a heat-dried
stoppered test tube, the mixture was exchanged with nitrogen and
refluxed. The product was reacted with acetic acid and concentrated
hydrochloric acid at 100° C. to obtain compound α-J
represented by the following formula (α-J) as the target substance.

##STR00065##

Example α-4

Synthesis of Compound α-K

[0312]After placing compound α-H, compound α-L represented by
the following formula (α-L),
tetrakis(triphenylphosphine)palladium(0) and toluene in a heat-dried
stoppered test tube, the mixture was exchanged with nitrogen and
refluxed. The product was reacted with acetic acid and concentrated
hydrochloric acid at 100° C. to obtain compound α-K
represented by the following formula (α-K) as the target substance.

[0313]A substrate was prepared by forming a silicon oxide film as the
insulating layer, by thermal oxidation to a thickness of 300 nm on the
surface of a highly doped p-type silicon substrate as the gate electrode.
The lift-off method was used to form on this substrate a comb-shaped
source electrode and drain electrode with a channel width of 38 mm and a
channel length of 5 μm. The electrode-formed substrate was subjected
to ultrasonic cleaning for 10 minutes in acetone and for 10 minutes in
isopropyl alcohol, after which it was irradiated with ozone UV for 30
minutes to clean the surface. An organic thin film of compound α-I
was accumulated on the cleaned substrate to a film thickness of 10 mm
using compound α-I synthesized in Example α-2, by vacuum
vapor deposition at a substrate temperature of 110° C. and a
deposition rate of 0.2 nm/min, to fabricate an organic thin-film device
1. The organic transistor property was measured by varying the gate
voltage Vg from 0 to 120 V and the source-drain voltage Vsd from 0 to 100
V for the organic thin-film device 1 in a vacuum, and a satisfactory
n-type semiconductor Id-Vg characteristic was obtained. The mobility
during this time was 5.6×10-2 cm2/Vs, the threshold
voltage was 20 V and the on/off ratio was satisfactory at 106. This
confirmed that the organic thin-film device 1 using compound α-I
effectively functions as an n-type organic transistor, and that compound
α-I can be utilized as an organic n-type semiconductor with an
excellent electron transport property.

[0314]The organic transistor device 1 also exhibited a satisfactory
transistor property when operated in air (approximately 20° C.),
during which the mobility was 1.6×10-3 cm2/Vs.

[0315]A substrate was prepared by forming a silicon oxide film as the
insulating layer, by thermal oxidation to a thickness of 300 nm on the
surface of a highly doped p-type silicon substrate as the gate electrode.
The substrate was subjected to ultrasonic cleaning for 10 minutes in
acetone and for 10 minutes in isopropyl alcohol, after which it was
irradiated with ozone UV for 30 minutes to clean the surface. An organic
thin film of compound α-I was accumulated on the cleaned substrate
to a film thickness of 10 nm by vacuum vapor deposition under conditions
with a substrate temperature of 110° C. and a deposition rate of
0.2 angstrom/sec. Au was formed to a thickness of 20 nm on the organic
thin film by vapor deposition through a shadow mask, to form a source
electrode and drain electrode with a channel width of 5.0 mm and a
channel length of 50 μm, thus fabricating an organic thin-film device
2. The transistor property was measured by varying the gate voltage Vg
and the source-drain voltage Vsd for the obtained organic thin-film
device 2 in a vacuum, and a satisfactory Id-Vg characteristic was
obtained. The mobility during this time was 1.6×10-2
cm2/Vs, the threshold voltage was 41 V and the on/off ratio was
satisfactory at 104. This confirmed that the organic thin-film
device 2 using compound α-I effectively functions as an n-type
organic transistor and, as in Example α-5, that compound α-I
can be utilized as an organic n-type semiconductor with an excellent
electron transport property.

[0316]Also, when the organic transistor device 2 was annealed for 30
minutes at 130° C. in a vacuum, the transistor property was
improved and the mobility was 2.6×10-2 cm2/Vs.

[0317]When the organic transistor device 2 was operated in air
(approximately 28° C.), it also exhibited a satisfactory
transistor property during which the mobility was 2.1×10-2
cm2/Vs. Even after standing in air (approximately 28° C.) for
24 hours, the organic transistor device 2 had a mobility of
1.3×10-2 cm2/Vs, thus confirming its stability in air.

Comparative Example α-1

Synthesis of Compound α-M

[0318]After placing 5,5'-dibromo-bithiophene (242 mg, 0.75 mmol),
4-acetylphenylboronic acid (366 mg, 2.23 mmol),
tetrakis(triphenylphosphine)palladium(0) (40 mg, 0.05 mmol), NaHCO3
(438 mg, 521 mmol) and a DME/water mixed solvent (7 mL) in a heat-dried
stoppered test tube, it was exchanged with nitrogen and reaction was
conducted at 100° C. After 14 hours, the mixture was concentrated
under reduced pressure to obtain a solid. The obtained solid was rinsed
with methanol and ether and then subjected to sublimation purification in
a vacuum, to obtain compound α-M represented by the following
formula (α-M) as the target product (205 mg, 83% yield), as a light
yellow solid. The reduction potential of compound α-M was
unmeasurable because the compound was insoluble.

[0320]Organic thin-film device 3 was fabricated in the same manner as
Example α-5, except that the organic thin film was formed of
compound α-M synthesized in Comparative Example α-1 instead
of compound α-I synthesized in Example α-2. The organic
transistor property was measured by varying the gate voltage Vg from 0 to
100 V and the source-drain voltage Vsd from 0 to 100 V for the organic
thin-film device 3 in a vacuum, to obtain the n-type semiconductor Id-Vg
characteristic. The mobility during this time was 1.8×10-5
cm2/Vs, and the on/off ratio was low at 102.

INDUSTRIAL APPLICABILITY

[0321]As explained above, according to the first invention group it is
possible to provide novel conjugated compounds that can be used as
organic n-type semiconductors with excellent electron transport
properties. It is also possible to provide organic thin films containing
the novel conjugated compounds, and organic thin-film devices comprising
the organic thin films.

[0322]According to the second invention group, it is possible to provide
novel nitrogen-containing fused-ring compounds and novel
nitrogen-containing fused-ring polymers that can be used as organic
n-type semiconductors with excellent electron transport properties. It is
also possible to provide organic thin films containing the
nitrogen-containing fused-ring compounds or nitrogen-containing
fused-ring polymers, and organic thin-film devices comprising the organic
thin films.